Impel Down

Impel Down (インペルダウン), the Great Jail, is the World Government's maximum-security prison for the most dangerous criminals and pirates. Its name derives from the English verb 'impel', meaning to force. Some translations use the word Gaol which is an early Modern English spelling for jail. It is located underwater in the middle of a Calm Belt.

Only Escape and Past Horrible Reputation
Twenty years ago, Kinjishi the Flying Pirate was the only prisoner to escape Impel Down until then, due to a mistake made by the Marines. Ever since then, no prisoner has ever made a successful break-out or break-in until recently.

Over the years, many prisoners of Level 5 would disappear for no apparent reason. The guards dubbed this phenomenon as "demoning" away, and thought such prisoners are gone forever. In truth, they were rescued from their cells by Revolutionaries commander Emporio Ivankov, who was also imprisoned in Level 5, and they all stayed at the secret Level 5.5, a space dug out by a past prisoner with a tunneling Devil Fruit power.

Chief Guard Shiryuu of the Rain has killed many prisoners within the walls of the prison for his sheer pleasure, and was deemed a menace. He was put on death row, and was held in Level 6 until his sentence would be carried out.

Baroque Works Downfall and Spark of the Whitebeard War
After the fall of Baroque Works at Arabasta, Crocodile (Mr. 0), Daz Bones (Mr. 1), Bentham (Mr. 2 Bon Kurei), and Galdino (Mr. 3) were all eventually transferred from a regular prison to Impel Down for life.

When Marshall D. Teach captured Portgas D. Ace to gain the Shichibukai title, Ace was transferred to Level 6, to be held there until his public execution.

Sometime around Ace's imprisonment, Buggy the Clown was captured by the Marines and sentenced to Level 1. His crew was thinking of saving him, but due to Impel Down's reputation of impregnability, they gave up and left him.

During the preparations for Ace's impending execution, Jinbei of the Shichibukai was sent to Level 6, as he refused to fight on behalf of the World Government, and even broke out on a rage in Marineford. He was placed in the same cell as Ace, who he was friends with for a long time.

Luffy's Break-In and Tarnish of the Perfect 20 Years Record
When Monkey D. Luffy heard of Ace's impending execution, he requested the newly befriended Shichibukai member Boa Hancock to help him enter the prison to help save his brother. Hancock, under the guise of wanting to see Ace, smuggled Luffy into the prison successfully. As an attempt to buy Luffy some time, she went to see Ace, and discreetly told him of Luffy's presence.

After teaming up with the old associates who escaped their cells: Buggy, Mr. 3 and Mr. 2, Luffy managed make it all the way to Level 4, defeating the Demon Guard Minotaurus and many other guards. However, this brought attention to the higher officers of Impel Down, and eventually, Chief Warden Magellan came in and fought against the Straw Hat Captain. After a grueling battle, Magellan fatally poisoned Luffy and had him imprisoned in the central tower of Level 5, until the poison kills him.

Mass Riot and Impel Down's Greatest Crisis
After Mr. 2 rescues Luffy (Buggy and Mr. 3 fled back to Level 2, after a series of carefulness and stealth), they were rescued by Inazuma, resident of Level 5.5 and a Revolutionary member. There, Luffy begged him and Ivankov to save Mr. 2 over his poisoned self. This caused Iva to be moved, and he saved them both, despite Luffy losing ten years of his life as a result.

When Luffy was healed in much less time than expected, he continued his quest to save Ace. Iva, who found out Luffy was the son of his leader, Monkey D. Dragon, decided to help out, as he thinks that the time for their escape is now. Along with Inazuma, the three made it to Level 6. Unfortunately, Ace has already been transferred to Marineford. However, as the trio attempted to take either the elevator or the stairs, sleeping gas began flooding through either way, forcing Inazuma to block both ways to save themselves. Crocodile then offered to help them if they are willing to release him from his cell, as he gets a chance to kill Whitebeard, though he did not expect Iva to be there, who so happens to use a "precious weakness" to keep the former Shichibukai in check. Jinbei also begged them to take him along, as he wanted to protect Whitebeard. With that, the five escaped Level 6.

When the security guards arrive to intercept the five escapees in Level 6, they found that they were too late. Shiryuu, however, offered to help them if he is released. Meanwhile, the five escapees, along with every resident of Level 5.5, are planning to cause a mass-breakout. To increase their chances, they decided to release every prisoner they can along the way back up to the exit. Among them, Crocodile personally released his comrade, Mr. 1, who agreed without question to leave.

As Buggy and Mr. 3 managed to sneak back to Level 2, they instigated the prisoners there for a second riot (the first being after leading Luffy down to Level 3, which was quelled by Chief Guard Saldeath and his army of Blue Gorillas). They were, however, stopped by Magellan. However, as Magellan left to deal with Luffy and his mass-breakout army, the Level 2 rioters were once again active.

Around the same time, Blackbeard, along with his entire crew, stole a Marine ship, broke in to the prison for their own reasons, stating they were on the same side, but attacking the guards regardless.

Magellan, seeing things in such chaos just because they let Luffy intrude, decided to suspend Shiryuu's death sentence, and let him out to fight against Blackbeard. However, this was prove to be a mistake, as rather than subduing Blackbeard, Shiryuu slaughtered many guards, disabled the giant Surveillance Den Den Mushi, and severed all communications to the outside world. Effectively, Shiryuu has not only prevented them from calling backup, but also destroyed all visual monitoring throughout the entire prison.

After the remaining Demon Guards were defeated by Luffy, Jinbei, and Crocodile, and Chief Guard Sadi-chan by Iva, Vice-Warden Hannyabal decided to handle the situation himself, and he had one thousand Bazooka Unit guards to stand guard between the threshold of Levels 3 and 4. He put up a great fight, but Luffy beat him bloody, and was finished off by Blackbeard, who also annihilated the entire Bazooka Unit.

Blackbeard and the rest of his crew had a few exchange of words and blows with Luffy, but were stopped by Jinbei, who reminded Luffy that saving Ace takes priority. The breakout army then headed for Level 3, while the Blackbeard Pirates continued forward, claiming they would shake the world, only to be poisoned by Magellan. As the army continued upwards, Magellan claimed that he would not let Luffy leave Impel Down alive.

Union of the Two Forces and Nearing the Outside World
As Luffy and his comrades from New Kama Land (the name for level 5.5) moved up the levels, Magellan pursued, killing many rioters on the way. Ivankov and Inazuma tried to hold him off, but both were eventually poisoned by him, and left defeated.

Upon making it to Level 1, Luffy's group met with Buggy's, who also managed to make it to Level 1. The guards of Impel Down assumed the two forces had joined together. Magellan then managed to reach them, and launched his Hydra at the group, at the same time ordering the ships outside for something that caused Jinbei to worry. As the Hydra approached, Mr. 3, in a sudden surprisingly selfless move, blocked it with his Candle Wall and told everyone else to run.

Sunlight, Wax Armor, and Ship Hunting
As Mr. 3's wax proves to be resistant to Magellan's Hydra venom, he encased Luffy's limbs with wax armor, allowing the Straw Hat captain to attack the prison warden without being poisoned any further. Some other prisoners also used cannons walled by the wax to backup Luffy against Magellan.

Meanwhile, Jinbei, Crocodile, Mr. 1, and Buggy, along with half of the breakout forces tried to secure a ship for their escape. However, when they reached the front doors, they find all the Marine ships were ordered by Magellan to leave port to prevent escape. As such, Jinbei, carrying Crocodile, Mr. 1, and Buggy on a makeshift raft, pursued the ships to bring one back for themselves.

The First Mass-Breakout and Impel Down's Ultimate Loss
After having his Hydra nullified by Mr. 3's wax armor, Magellan decided to bring out his ultimate attack: Venom Demon: Hell's Judgment, a Devil-like creature created from his most powerful poison, Kinjite, and has the power to destroy the entire Impel Down. The poison proved to be too powerful, and spreads like a disease that renders even stones and wax useless. With no options left, Luffy, Mr. 3, and the other prisoners fled for the exit, with some prisoners getting caught by the toxin.

Although the survivors made it to the outside, the ships Jinbei managed to procure was still too far to return in time. As though all hope is lost, suddenly Iva and Inazuma came bursting out from Level 1. At the same time, Jinbei contacted them through a Den Den Mushi, telling Luffy's group to jump into the ocean. Luffy, trusting Jinbei, combined his Gear Third attack with Mr. 3's extra thick Giant Candle Wall to push Magellan's Hell's Judgment back for a few seconds. Then with Iva's Hell Wink, with everyone grabbing onto his oversized head, they were launched into the air and towards the Calm Belt. There, a huge school of whale sharks came and saved them, thanks to Jinbei's summons.

The Ultimate Sacrifice and Impel Down's Disgrace
After the whale sharks dropped off all the prisoners on the escape ship, they headed for the Gates of Justice, only to realize that it won't open for them. With the gate as the final line of defense, the Marine battleships began to fire at the escapees. Magellan ordered a battleship to come to pick him up, so he can deal with the prisoners himself. However, as though Luffy and his comrades were trapped and doomed, the Gates suddenly opened, much to the surprise of everyone but Jinbei.

Back inside the generator room of Impel Down, Magellan was there, ordering the openings of the Gate, much to the confusion of the guards. The Magellan outside of the prison ran back to the generator room, and while demanding an answer for why the Gates opened, he met with the Magellan there.

It turns out that Mr. 2 has chose to left behind, and using his powers to impersonate Magellan, to open the Gates of Justice for Luffy and the rest of them. He had told Jinbei all of this beforehand, and requested that this would be revealed to Luffy only after the ship left through the Gates, so the Baby Den Den Mushi's signals would not be able to send through anymore.

However, Jinbei gave Luffy a Den Den Mushi before the ship passed through, and allowed him and Mr. 2 to have one last talk. After a tearful "Thank You" from most passengers on the escape ship, they parted ways. Magellan then began to attack Mr. 2, who stated that he has no regrets; the outcome of the fight is unknown. With that, Impel Down has suffered its ultimate disgrace, allowing 241 prisoners to escape its walls.

Breakout Aftermath and Blackbeard's Offer
After the mass-breakout, Impel Down was left in ruins. The Blackbeard Pirates, who were poisoned by Magellan, were given an antidote by Shiryuu. Blackbeard then gave his savior a second offer to join his crew, to which the latter agreed, knowing the alternative is death sentence, and that he was waiting for a man of Blackbeard's stature for a long time.

Entering Impel Down
Impel Down is located in the middle of the Calm Belt, where Sea Kings thrive, making entrance difficult. The only way to get there with the greatest of ease is to use the Tarai Current, a water current accessible by going through the Gates of Justice located at either the Marine Headquarters or Enies Lobby. Also, the only way to safely get to the prison is to use one of the Seastone lined Marine battleships, as the entire place is surrounded by Sea Kings.

Because of its brutal nature and being renowned for being inescapable since Kinjishi, almost no person wishes to ever go there. However, there are people who choose to enter it willingly: such as Monkey D. Luffy, Daz Bones and Crocodile.

Usually, Impel Down is a hell-fortress with maximum defenses, making intrusion and breaking-out by criminals impossible. However, Luffy made the record of being the first to break-in, tarnishing that perfect record since Kinjishi's breakout twenty years ago. The Blackbeard Pirates are the second group of people to ever instigate a break-in, and they did so with less effort than Luffy, not having bothered to try to avoid detection.

Arrival and Sterilization
When prisoners arrives in Impel Down, they are put in boiling water to disinfect and sterilize them. This is ritualistically referred to as "baptizing" them.

While most have screamed in pain due to the extreme heat, only a few prisoners have been known to take the sterilization without flinching even one bit. These prisoners include Portgas D. Ace, Jinbei, and Crocodile.

Monkey D. Luffy is the only known prisoner to not have gone through this ritual, being an intruder who was supposed to die in twenty-four hours from poison.

Change of Clothing
Most prisoners then have their clothes taken before they are given a striped black and white shirt and trousers. However, they are permitted to keep certain articles of clothing, such as Mr. 3's glasses, and Crocodile's hook.

Exceptions to this rule are prisoners who were not meant to stay long before death. These include Portgas D. Ace, Monkey D. Luffy, and Shiryuu. Jinbei was also allowed to keep his own clothing, as he was meant to be kept there until he was willing to cooperate with the World Government.

The residents of New Kama Land seem to have managed to retrieve their old clothes after escaping from their cells. Similarly, Crocodile seems to have somehow retrieved clothing similar to his old attire, including a long fur coat, almost immediately after escaping from his cell.

Level Assignment and Life of Torture
After sterilization and a change of clothing, the prisoners are then placed in one of the six known levels of Impel Down, based on their crimes and strength. The more heinous or powerful a prisoner is, the lower the level they will be placed. From then on, the prisoners are tortured everyday in various ways, depending on their assigned levels, with most of them supposedly having no chance of ever leaving alive.

Visits
Whether outside people are permitted to visit the prisoners is unknown. Government agents and Marines have the authority to do so, but they would need permission from their superiors.

As Impel Down is a World Government facility, it is obvious pirates cannot enter without being branded as intruders and criminals. The Shichibukai are allowed, at the permission of the Government. Even so, they would be subjected to a full body search, then be forced to wear Kairoseki-cuffs, for safety measures. Without permission, such as Blackbeard and his crew, they would be considered as traitors.

Leaving Impel Down
Aside from visitors and Government officials, most people who enter Impel Down never leave there alive. The only prisoners ever allowed to leave are those who are held until their death penalty that takes place outside of the fortress (i.e. Portgas D. Ace) and those who are meant to serve temporary sentence (i.e. Jinbei).

Breakout of Impel Down is virtually impossible, due to the defenses from the extremely powerful traps and guards of the place, with the Sea King-infested Calm Belt being its ultimate barricade. However, Kinjishi made the record of being the first person to break-out of the prison twenty years ago due to a mistake made by the Marines. Monkey D. Luffy became the second to do so.

Aside from his own escape, Luffy is also responsible for leading the very first mass-riot within the Gaol. And, along with Emporio Ivankov, Inazuma, Buggy, Daz Bones, Crocodile, Jinbei, Galdino, and 233 other prisoners, he is also responsible for the first-ever mass breakout in Impel Down's history. Bentham intentionally stayed behind, sacrificing himself to let the others complete their escape. It is unknown how many prisoners died during this riot, mostly by the Demon Guards and Magellan's poison.

General Layout
Impel Down is a large submerged tower-like structure whose foundation is at the very bottom of the sea bed. Due to it being built within the Calm Belt, the entire structure is constantly surrounded by gigantic Sea Kings swimming below the water. Along with these beasts, the prison is guarded by a force of Marine battleships.

Within the dark confines of the prison are various cells and torture chambers that used for the prisoners. The cells are all made from seastone to keep those with Devil Fruit powers from escaping. The torture chambers are used for all sorts of brutal unspeakable acts. Among these include continuous whipping, brutal beating to death, boiling cauldrons for burning and drowning, and spiked pits used for impaling.

The prison is carefully monitored all around by a Surveillance Den Den Mushi. Tiny versions of them are found in specific locations throughout Impel Down. Whatever they see is transferred to a larger version that sends video feeds to monitors connected to it, allowing the guards to keep surveillance. Each of the smaller versions has an alarm beeper connected to the shells. The large Surveillance Den Den Mushi is kept in a monitor room somewhere within the fortress. There is also what appears to be a medical laboratory stationed somewhere within the great jail, with doctors and a variety of medical equipment for immediate treatments of anyone within the prison, both prisoner and staff alike. However, the doctors seem to have a limit, as they cannot produce a cure for an accumulation of various poisons.

The generator room of the entire prison is located on the first floor, before Level 1, and as are the controls to open the Gates of Justice.

Levels
A prisoner's assigned level is usually determined by the bounty value on his or her head. Although with exceptions, such as Crocodile whose bounty was removed a long time ago and Mr. 2 Bon Kurei, when the Government acknowledges their strength is obviously superior to their bounties.

Along with various cells to keep inmates, each level possesses a unique form of torture. Because of these unspeakable acts being performed, each level is given the title of hell. With each descending level, the torture worsens.

Level 1: Crimson Hell
Crimson Hell (紅蓮地獄) is the first level of Impel Down in which prisoners are kept. While the level relatively is used for less wanted criminals, it contains a large forest of red trees. The leaves of the trees, known as Kenju (剣樹), are as sharp as blades while the grass on the floor, the Haribarisō (針々草), is as spiky as needles. Here prisoners are forced to run through the forest while being chased by poisonous spiders and guards to experience all the pain from being cut from all directions. As consequence of prisoners being forced through this forest, it is soaked in blood. Deep within the forest is a hole that leads to Level 2. For those who do not wish to live through the pain of being cut any longer, they were given the option of jumping down the hole to Level 2, which contains an even more terrifying hell that nobody is willing to risk. The security here seems to be somewhat lax, as a prisoner has managed to sneaked a Black Den Den Mushi into his cell, eavesdropping on what is happening around the fortress.

Buggy was kept here prior to his escape due to the guards not knowing he was a Devil Fruit user, much less one whose power rendered him completely impervious to this type of torture.

Level 2: Wild Beast Hell
Wild Beast Hell (猛獣地獄) is the second level of Impel Down in which prisoners are kept. Buggy commented that every prisoner from level 2 that escaped with him holds a bounty higher than his own (15,000,000 Beli). It contains various wild beasts of sorts. The beasts kept here include Puzzle Scorpions and Manticores. Puzzle Scorpions are large poisonous insects that can join together to become giant centipedes. Manticores are man-eating human faced lions that will devour everything from their prey including the bones. Their human faces allow them to speak however they can only imitate what they hear like parrots as they don't understand what they're actually speaking. The words they speak are mostly things they heard from the prisoners so some of the things that they say are completely out of place. Among these regular-sized beasts kept here are also two gigantic beasts, the Basilisk and the Sphinx.

The Basilisk is a gigantic snake born from a chicken. It is a feathered mutant that possesses both snake and chicken traits. It is extremely strong that it gave Luffy and Buggy a good chase until it was downed with one blow of Gear Third from Luffy. Though formidable, the Basilisk is not the most powerful beast in the level. It is considered to be the "second-in-command".

The Sphinx is a gigantic human faced feathered lion. Significantly larger than the Basilisk and much more fearsome than the other beasts, it is considered the "boss" of the level and is charged with guarding the stairway that leads out of the level. It is so fearsome that the prisoners kept in the level, and even the other beasts hide from it. Like the Manticores, it is capable of imitated speech. It randomly says the names of types of noodles and apparently understands the concept of giving thanks before meals. It is such a strong beast that it is capable of breaking the floor beneath it if it hits it enough times.

With these various beasts, prisoners kept here are forced to be chased by them through the corridors of the level. Because of the fearsome danger, prisoners often either lose the will to go on, or refuse to escape even when their cells are unlocked.

Mr. 3 was kept here prior to being set free by Luffy and Buggy. After both the Basilisk and the Sphinx were defeated, and along with all the prison doors being unlocked, there was a mass riot in the level caused by Luffy and his companions. The riot however was quelled down by Saldeath and his Blue Gorillas. There was recently another riot that occured shortly after the previous riot but has since been quelled after Magellan apparently decimated almost all the prisoners on the level and blocked all the entrances and exits. However, as Magellan is now occupied with Luffy's breakout army, the rioters of Level 2 is once again active.

Level 3: Starvation Hell
Starvation Hell (飢餓地獄) is the third level of Impel Down in which prisoners are kept. Most of the prisoners kept here are pirates who have a bounty of 50,000,000 or higher. On this level, prisoners feel the heat rising up from Level 4 and are given precious little food and water to keep them in a near death state. They are reduced to the point where merely looking at them cannot tell that they were anywhere near once frightening criminals. And while the temperature here is nothing compared to the following level below, it is intense enough to cause overwhelming dryness, resulting in Level 3's somewhat desert-like terrain. Mr. 2 Bon Kurei was kept here, despite his bounty being only 32,000,000.

In the middle of the level is a large hole going directly to Level 4 down below. This combined with a gigantic fan directly above the hole, serves as the main ventilation system to redirect the smoke produced from below. Level 4 can be reached through this hole, however, to travel down it holds a risk of death or scalding by the fire and heat of the floor below.

Level 4: Blazing Hell
Blazing Hell (焦熱地獄) is the fourth level of Impel Down in which prisoners are kept. At this level, a pool lies filled with boiling blood heated by a raging fire making it extremely hot. The heat caused by this is so intense that it also heats up the level directly above it. If one tries to jump down to this level from Level 3 using the large hole used for ventilation above but don't land on a safe place, then they're dead.

Prisoners from other levels are regularly tortured here. The most prevalent form of torture here however is being thrown into the gigantic pot of boiling blood in the middle of the level.

Mr. 1 was kept here, though he was shown to be unfazed by the heat of this level while being placed in hard labor. He also saw Luffy and Magellan's battle while in his cell.

Magellan the warden of Impel Down stays here. His office contains a lift, which can take several people to all the Levels throughout the fortress, bypassing the stairs. This is also where the kitchen of the prison is located next to Magellan's office. Luffy's battle with Magellan was fought here prior to him being completely poisoned and captured.

Level 5: Freezing Hell
Freezing Hell (極寒地獄) is the fifth level of Impel Down in which prisoners are kept in. This is the level where criminals with bounties of 100,000,000 and over are kept. In stark contrast to the level above it, the entire level here is a giant freezer. The level is so cold that not only do the prisoners kept here either freeze to death or lose pieces of their flesh from severe frostbite, but the food given to them is frozen to the level of being virtually inedible. Due to the extreme cold, Den Den Mushi don't function in this Level, thus cutting off both contact and surveillance, except on the locations localized around the entrances that connects Level 5 to the previous and next levels. Along with the severe cold, the level is inhabited by wolves. These wolves roam around the level like the beasts of Level 2, where they were originally stationed at. However, they proved to be too brutal to be in Level 2 as they also hunted the other beasts as well, including the Basilisk and the Sphinx.

Along with the bitter cold of the level, there seems to be a occurrence of prisoners mysteriously disappearing as well. Prisoners who are incapable of moving by themselves have been disappearing without a trace. Because of this, the Impel Down staff and the prisoners call this phenomenon, the "demoning away". The superstition is that the missing prisoners have been actually pulled away by demons to the Gates of Hell itself. The belief of this superstition has been carefully kept within level 5 so that no inmates from the upper levels were aware about it prior Bon Kurei (disguised as Hannyabal), Buggy, and Mr. 3 descending down to it where they were informed by the guards. Among these missing prisoners is Emporio Ivankov, the queen of the okama. He was imprisoned here until he mysteriously disappeared from his cell. Since then he was rumored to be living in an abandoned guard's office deep within a forest situated in the level.

Luffy was transferred into the central tower of this floor after his loss against Magellan, until released by Bon, hoping to find a cure.

Level 5.5: New Kama Land
Known as the The "Prisoners' Secret Flower Garden", New Kama Land (番地ニューカマーランド) is a hidden sub level of Freezing Hell, and is where all the prisoners who have been supposedly "demoned away" have gone to. The secret area is located inside rock between Levels 5 and 6. It was carved out long ago by a prisoner with a tunneling Devil Fruit power, and is a secret location unknown by the jailers. It is ruled by the "Queen" Emporio Ivankov, and it's called the Okama Paradise where all the Okama and prisoners party and have fun at all times. Indeed, it has been described by Iva as a "paradise within hell", and true enough, not one inmate from this hidden level is inclined at all to escaping the Great Jail as a result.

One of its main rooms is a combination of a sit-down cafe and a discotheque, with the main attraction being a cabaret stage where Emporio Ivankov and his followers perform The level also has a Surveillance Den Den Mushi so the prisoners can see what's going on from all levels in the prison. They also steal newspapers from the prison's garbage cans to stay informed of current events.

It's name is a pun on New Comer and Okama, and refers to the Okama who are completely able to change genders thanks to Iva's powers.

Level 6: Eternal Hell
Eternal Hell (無限地獄) is the lowest level of Impel Down. It is where prisoners who are insanely powerful, have caused crimes extremely atrocious, or whose mere existences have become a major threat to the World Government itself are kept. The prisoners on this level have been given either the death penalty or a life sentence. They are basically "erased" from history.

Ace was kept here on death row, awaiting his execution. Because most people dismiss Level 6 as just a rumor (until its actual discovery) Ace was believed to be on Level 5 by other prisoners. Jinbei was also placed on this floor, and was being kept in the same cell as Ace. Though the prisoners on this floor are either jailed for the rest of their lives or until their execution day arrives, Jinbei was only given a temporary sentence for refusing to fight against Whitebeard. Crocodile is also being kept here in a cell next to theirs. Near them are various other legendary pirates who hold deep grudges against Whitebeard, some of which are several imprisoned Giants.

Kept alongside the prisoners is the former Chief Guard Shiryuu. Because he constantly massacred prisoners, he was deemed to be a menace even within Impel Down, and became too dangerous to be kept anywhere else in the prison. For abusing his powers, he was sentenced to Level 6.

High Ranking Staff

 * Magellan: Chief Warden (監獄署長), resides in Level 4, possesses the Doku Doku no Mi, only serves about four hours of service.
 * Shiryuu: Former Head Jailer, Magellan's equal, abuse of privilege, stripped of status and sentenced to death row in Level 6, sentence postponed and released for assistance, betrayed the prison and defected towards the Blackbeard Pirates.
 * Hannyabal: Vice Warden (副署長), ambitious person, Magellan's chosen successor.
 * Saldeath: Chief Guard (牢番長), commander of the Blue Gorillas.
 * Sadi-chan: Chief Guard (獄卒長), sadistic torturer, commander of the Four Demon Guards.
 * Domino: Vice Chief Guard (副看守長).

Guards

 * Human guards: Either stationed in the monitor room or various other places. They vary in duties.
 * Bazooka Unit: A group of thousand troops holding large, bullet bazookas.
 * Blue Gorillas: Super strong and mindless gorillas with doubleheaded axes, under the command of Saldeath. Mainly reside in Level 1, but can be called to other levels.
 * The Four Demon Guards: Four fearsome guardians of Impel Down, under the command of Sadi-chan. They are all "awakened" Zoan-class Devil Fruit users.
 * Minotauros: A bipedal bull who beats up prisoners often.
 * Minorhinoceros: A bashful bipedal rhinoceros.
 * Minokoala: A bipedal that is also an armed fighter.
 * Minozebra: A shy bipedal zebra who pushes prisoners into the lake of blood

Other Beasts

 * Basilisk: Giant snake born from a chicken that shares traits of both creatures.
 * Manticores: Man-eating, human-faced lions that can eat their preys completely. Has the ability to talk but not understand what they are saying.
 * Puzzle Scorpions: Extremely poisonous creatures that can unite to form giant centipedes.
 * Sphinx: Boss of the level, extremely strong and guards the stairs. Also has the ability to talk but likewise with the manticores has no understanding of what what it is saying.
 * Hummingbirds: Wild beasts also found in Level 2. Only one has been shown.
 * Wolf Unit: Extremely vicious wolves that prey on even other beasts, relocated to Level 5.
 * Giant-Mouth Hippo: (Anime only) Deceptively diminuitive hippoes who are capable of running very fast (but can't turn well) and stretching their mouths to swallow larger prey (i.e. prisoners) whole.
 * Giant Praying Mantis: (Anime only) A humanoid species of praying mantis skilled in fighting that uses its sword arms to try to slice intruders to pieces. Wears a uniform similar to that of an Impel Down guard.

Prisoners

 * Crocodile: For abusing his Shichibukai title, founding the Baroque Works organization and attempted coup d'etat of the Arabasta Kingdom; Life sentence, Level 6; Escaped.
 * Daz Bones: For being an infamous assassin and a member of Baroque Works; Life sentence, Level 4; Escaped.
 * Bentham: For being a member of Baroque Works; Life sentence, Level 3, Prisoner number C9915; Helped Luffy and the others escape but stayed behind, Last shown about to face off against Magellan, Current status unknown.
 * Galdino: For being a member of Baroque Works; Life sentence, Level 2, Prisoner number D0464; Escaped.
 * Portgas D. Ace: For being a member of Whitebeard Pirates, the son of Gold Roger, and to root out the possibility of him being raised to be the new Pirate King; Death penalty, Level 6; Transfer of custody to Marines complete.
 * Jinbei: For causing an uproar at Marine Headquarters and refusing to fight on behalf of the World Government; Temporarily sentenced, Level 6; Escaped.
 * Buggy the Clown: For piracy; Level 1, Prisoner number E8200; Escaped.
 * Emporio Ivankov: Revolutionary; Level 5; Residing in Level 5.5; Escaped.
 * Kinjishi: Escaped 20 years ago.
 * Monkey D. Luffy: For infiltrating Impel Down in attempt to break Portgas D. Ace out of prison; Death by poison in 24 hours, Level 5; Received treatment in Level 5.5; Escaped.
 * Roche Tomson: Reason unknown; Level 5.
 * George Black: Reason unknown; Level 5.
 * Inazuma: Revolutionary; Level 5; Residing in Level 5.5; Escaped.
 * Unknown Devil Fruit User: An unknown prisoner who had the ability of tunneling Devil Fruit. He was the original creator of Level 5.5.
 * Shiryuu: For killing too many prisoners; Postponed death penalty, Level 6; Released to fight, defected towards the Blackbeard Pirates.
 * Catarina Devon: The world's worst female prisoner in the entire pirate age; Life sentence, Level 6.
 * San Juan Wolf: Reason Unknown; Life sentence, Level 6.
 * Basco Shot: Reason Unknown; Life Sentence, Level 6.

Prisoners' Profile
Crocodile and Mr. 1 were imprisoned in a Marine base, but were transferred to Impel Down after most of the captured Baroque Works members escaped (Crocodile and Mr. 1 chose to stay behind). Currently, Both Crocodile and Mr. 1 has joined Luffy, Iva, Inazuma and Jinbei to escape Impel Down. after defeating the Four Demon Guards, the two made it to Level 1, only to find Magellan closely pursuing them, and ordering the Marine ships back to prevent them stealing them and escaping. Jinbei then made a makeshift raft to allow them to stand on it as he swims them across, and with his Fishman Karate abilities underwater, catapult them onto a Marine ship, which they successfully took over.

Mr. 2 Bon Kurei and Mr. 3 were captured by Hina, and presumably transferred to Impel Down for reasons similar to Crocodile and Mr. 1's transfers. Currently, both Mr. 3 and Mr. 2 Bon Kurei have left their cells and are teamed up with Luffy and Buggy. While Mr. 2 Bon Kurei is healing in Level 5.5, Mr. 3 is wandering in Level 5 with Buggy. They were able to sneak their way to Level 2, where they proceed to starting another prison riot. Mr. 2 had taken Emperio Ivankov's Vigour Hormones and joined Luffy, Crocodile, Mr. 1 and Jinbei at Level 4. Making it all the way to Level 1, Mr. 2 had to wait until Crocodile, Jinbei and Mr. 1 successfully capture a Marine ship to escape to Marine Headquarters despite time being on the essence with Magellan pursuing them. Mr. 3 aided Luffy in fighting back Magellan, and used wax shielding on the cannons the prisoners fired at the Chief Warden. As soon as Magellan used Kinjite. a poison powerful enough to dissolve the wax, he, Luffy and the other inmates took off, only to finally use a massive wall of wax which Luffy pushed to slow down Magellan's advance. He escapes with the other prisoners by holding on to Iva's massive head, which propels them to the outside, where he is brought to the captured Marine ship by Jinbei's summoned whale sharks

Defeating Portgas D. Ace led to Blackbeard becoming a Shichibukai, and Ace being sent to Impel Down. Ace is currently sentenced to public execution. With the prospect of Whitebeard's and Monkey D. Luffy's attempts to rescue him, and that his escape would shake the foundations of the world, Ace is possibly the most important prisoner of Impel Down at this time. He is currently being escorted by the Marines to be transferred to Marine Headquarters.

Jinbei caused a wild outburst during his summons in the Marine HQ, and is sent to Impel Down until he is calmed, but he shows no signs of folding. He has been released from his cell by Luffy, Iva and Inazuma to assist them in breaking out of Impel Down. After defeating the Four Demon Guards and meeting Blackbeard, the man responsible for Ace's imprisonment, and ultimately the war the World Government is due to commence with the Whitebeard Pirates, Jinbei, Crocodile, Mr. 1, Mr. 2 Bon Kurei, Mr. 3, Buggy and Luffy made it to Level 1 after Blackbeard, Iva and Inazuma gained enough time for the others to escape by slowing Chief Warden Magellan down. Seeing that Magellan ordered all ships back to prevent them from escaping, Jinbei made a makeshift raft from the door of the Great Gaol for Crocodile, Mr. 1 and Buggy to stand on, Jinbei then uses his Fishman Karate which has far greater power underwater to launch the raft carrying the three into a Marine ship were they defeated the Marines on board. After Luffy and Mr. 3 held off Magellan, Jinbei through the Den Den Mushi ordered them to escape through the sea, and with Iva's help the escapees made it out of Impel Down and were rescued by whale sharks under Jinbei's command, allowing the first ever mass-breakout of Impel Down's history.

Buggy the Clown was transferred here after being captured after leaving the island he mistook for Treasure Island. Buggy managed to escape his cage in Impel Down, but it is unknown whether his acquaintance with Ace has any effect on his recent capture at Impel Down. With Luffy currently breaking in Impel Down to rescue Ace, he has teamed up with Buggy to get there, and fight off any guards that come on their way. Currently, Buggy and Mr. 3 are wandering in Level 5, after fleeing from the wolves. They were able to sneak their way to Level 2, where they proceed to starting another prison riot. After Luffy with Mr. 2 Bon Kurei, Mr. 1, Crocodile, Jinbei and Luffy made it to Level 1, they realized that the Four Demon Guards had followed them and were dispatched yet again, along with Chief Warden Magellan hot on their tail. With Magellan ordering the ships to move back to prevent their escape, Jinbei made a makeshift raft out of the door entrance of Impel Down, and used it to allow Crocodile, Mr. 1 and Buggy to stand them on it while he swims them across. While the inmates Buggy freed believed he stood on the raft to start a battle worthy of the Shichibukai, he merely stood there to make an easy escape of Magellan's wrath and have Crocodile and Jinbei help him get rid of the Marines and escape. However, when Jinbei launched the three onto a Marine ship, Buggy was the only one who didn't make a safe landing and was knocked out as he fell on board, and remained so until the capture of the Marine ship was nearly complete.

The former "queen" of the Kamabakka Kingdom, Emporio Ivankov, was arrested and sent to Level 5 of Impel Down "without rhyme nor reason". However, he escaped from his cell and founded Level 5.5: New Kama Land, and took other prisoners to take refuge in the "Okama Paradise", Inazuma being one of them. Both of them are Revolutionary members, and have been waiting for their leader to declare war before plotting a break-out. However, with the news that both of Dragon's sons are here in Impel Down, they decided the time is now, and decided to help Luffy rescue Ace. He has freed former Shichibukai Crocodile and Shichibukai Jinbei to escape the confines of Impel Down and rescue Ace. After making it as far as Level 3, personally defeating Guard Sadi-chan, he witnessed Blackbeard make it to the same level, which proved instrumental in ensuring that their escape is successful. After allowing the prisoners make it to Level 2, Iva ordered Inazuma to block the entrance as he goes up thew level so that he can slow Chief Warden Magellan down, and is quickly defeated by Magellan's poison. However, after using Face Growth Hormones in conjunction with Hell Wink, he made it with Inazuma to make it to Level 1, albeit knocking himself out in the process. When he regains consciousness, the prisoners grab on to his giant head as he fires a Hell Wink to propel them out of Impel Down, and were rescued by a school of whale sharks Jinbei communicated with to rescue them, making Iva's breakout plan successful.

20 years ago, Kinjishi the "Flying Pirate" made the only successful breakout of Impel Down, due to a mistake of the Marines.

Being the first person to break into Impel Down, Monkey D. Luffy eventually lost to Magellan in battle, and was coated in the lethal poison of the Hydra, which was to kill him after 24 hours of pain. Despite this, Magellan still ordered Luffy to be locked up into the central tower of Level 5, just to be sure. He was taken out of his cell by Mr. 2 Bon Kurei, and was being healed in Level 5.5. He had made a miraculous recovery and is assisted by Emporio Ivankov and Inazuma, two Revolutionaries who are also plotting escape. Luffy has released and is also joined by his old nemesis, Crocodile, and Jinbei to aid them them in escaping Impel Down and head to Marine Headquarters. After meeting Marshall D. Teach again and realizing he is also "Blackbeard" who got Ace to face public execution, he made it to Level 1 breifly fought Magellan again with the help of Mr. 3, and with Iva's help, escaped Impel Down and was saved by a school of whale sharks under Jinbei's command, completing the first mass-breakout in Impel Down's history.

Roche Tomson and George Black are some of the Level 5 prisoners listed on the list Mr. 2 Bon Kurei (disguised as Hannyabal) was reading from.

An unknown Devil Fruit user with tunneling powers created Level 5.5.

Shiryuu of the Rain is a former chief guard of the prison, and Magellan's equal. But due to his abuse of privilege of killing prisoners, he has been labeled as a menace and sentenced to Level 6. He was given a death sentence, but it was postponed and is currently released in order to help the short-handed Impel Down. Unfortunately, he was killing guards and damaging the prison, rather than follow his duties. Shiryuu later has saved the Blackbeard Pirates from Magellan's Hydra and joined their crew, after a second offer.

During Iva's explanation about Level 6, he mentioned legendary pirates that have been imprisoned there: Catarina Devon, "Colossal Battleship" San Juan Wolf, and "Mighty Drinker" Basco Shot are some of them.

Translation and Dub Issues
Impel Down title is often translated as "the Great Gaol", "gaol" is an old english word for "jail" or "prison".

Trivia

 * Various influences of "Hell" are present within its walls:
 * Impel Down seems to be heavily based on how Hell is described in Dante Alighieri's Divine Comedy. Both are level-based, "inescapable" prisons with unique forms of punishment per level, and the lower one traverses, the worse the punishments become. Consequently, Luffy's journey to the fifth level of Impel Down can be likened to Dante's descent.
 * Level 3 is in direct irony to the one in Dante's tale, where the third level of Hell was said to be realm of the gluttons. In Impel Down, Level 3, the Starvation Hell, is where the prisoners are constantly starving
 * Level 4: Blazing Hell is a typical representation of Hell in cultural and fictional references, with intense flames and heat burning the "sinners" (or in this case, prisoners), while a demonic figure (in this case, the Demon Guard Minozebra) pushing sinners into the flames.
 * A few of the levels of Impel Down also seem to resemble Buddhist concepts of hell such as the Crimson Hell which seems based on the "Hell of the Sword Tree and Knife Hill" which similarly tortures its victims by forcing them to run upon or impaling them upon trees and hills covered with knives and swords. Also the Four Demon Guards seem to resemble the demon guards Horse Face and Ox Head.
 * Each of the high ranking staff members seems to have a devil theme in their dress codes, a reflection to how each level of Impel Down is called Hell.
 * The Basilisk featured in Impel Down is based on a common mistake. Often depictions of the Basilisk show a "chicken-like" snake creature, but such a creature is actually known as a Cockatrice, as the legends are commonly mixed up.
 * Impel Down prisoners are assigned a 4-digit number preceded by a single letter that appears to denote what floor the prisoner is to be held at, starting with E for level 1 and presumably ending with A for Level 5. It is unknown what letter would be given to Level 6 inmates, or if they are even assigned numbers.
 * Four Shichibukai have entered Level 6 of Impel Down, the Great Jail:
 * Crocodile received a Life sentence for abusing his Shichibukai title, founding the Baroque Works organization and attempted coup d'etat of the Arabasta Kingdom.
 * Jinbei was sentenced to a temporal imprisonment for causing an uproar at Marine Headquarters and refusing to fight on behalf of the World Government.
 * Boa Hancock has smuggled Luffy in to prison, under the guise of wanting to see Ace.
 * Blackbeard, though has yet reached Level 6, has infiltrated Impel Down and made it to Level 4 with his crew.
 * During the Enies Lobby arc, Franky was ordered to be sent to Impel Down but he was pushed off a pit after he burned the blueprint. Nami orginally thought Robin would be sent to Impel Down