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. It's symbol resembles the Nazi Swastika and is like it in many ways such as the arm bands worn by the staff resembles the arm bands worn by Nazi officers. 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. The only way to get there with the greatest of ease, one must use 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 Sir Crocodile.

General Layout
Impel Down is a large submerged tower like structure that 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 King's 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 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 a machine it's connected too, allowing the guards to view video screens. Each of the smaller versions has an alarm beeper connected to the shells.

Levels
When a prisoner arrives in Impel Down they are put in boiling water to disinfect and sterilize them. This is ritually 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 Ace, Jinbei, and Crocodile. After being sterilized, they are then placed in one of the five 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.

A prisoner's level is by default determined by the bounty value on his head. Although with exceptions, such as Crocodile whose bounty was removed a long time ago and Mr. 2 Bon Kurei.

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. There is also what appears to be a medical clinic stationed somewhere within the great jail, loaded with various medicines and medical equipment for the immediate treatment of anyone within the prison, both prisoner and staff alike

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 Haribarisou (針グ草), 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 Msuhi 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 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. 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 most powerful beast in the level.

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 guarded 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 is currently being quelled down by Saldeath and his Blue Gorillas.

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 over 50,000,000. 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. 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.

Magellan the warden of Impel Down stays here. 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 whose bounties are more than 100,000,000 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 frostbites, but they are unable to eat properly the frozen food that is given to them. Due to the extreme cold, Den Den Mushi don't function in this Level, thus cutting off both contact and surveillance. Along with the severe cold, the level is inhabited by wolves. These wolves roam around the level like the beasts of Level 2. They were originally stationed at Level 2 like the other beasts. 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 that no inmate 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 is 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, where he will be dead from the latter's poison in 24 hours though Bon has recently broken him out of his cell and trying to find Iva in hopes of a cure.

Ace is believed to be kept here by most of the other prisoners in the upper levels. In the same cell as Ace's, Jinbei is kept alongside him. Crocodile is also being kept here in a cell next to theirs. Near them are prisoners that are various pirates with deep grudges against Whitebeard. These prisoners include imprisoned giants alongside them. However, the cells these prisoners are being kept at seems to have different surroundings compared to the icy environment of Level 5, suggesting either certain portions of this floor is not as cold as the rest, or they are not in Level 5. However, this is yet unknown.

Level 5.5: New Kama Land
Known as the The "Prisoners' Secret Flower Garden", New Kama Land 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 Level 5's sewage system, and is a secret location unknown by the jailers. It 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. It seems to consist of prisoners from multiple floors, as a woman asked Mr. 2 Bon Kurei what floor he was from. It is ruled by the "Queen" Iva, and it's called the Okama Paradise where all the Okama and prisoners party and have fun at all times. 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. Currently Luffy and Bon Kurei are here while Luffy is being healed.

Level 6
A mysterious level rumored by the prisoners to exist deeper than Level 5. It is said to keep criminals who are so powerful and dangerous that they have been erased by history.

While it is unknown whether it exists or not, the layout of Impel Down has a structure below Level 5

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.
 * Hannyabal: Vice Warden (副署長), ambitious person.
 * 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.
 * Blue Gorillas: Super strong and mindless gorillas with doubleheaded axe. Mainly resides in level one. Can be called to other levels.
 * The Four Demon Guards: Four fearsome guardians of Impel Down, under the command of Sadi-chan.
 * 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.
 * Wolves: Extremely vicious wolves that prey on even other beasts, relocated to Level 5.

Prisoners

 * Kinjishi: Escaped 20 years ago.
 * Sir Crocodile (Mr. 0): For abusing his Shichibukai title, founding the Baroque Works organization and attempted coup d'etat of the Arabasta Kingdom; Life sentence, possibly Level 5.
 * Daz Bones (Mr. 1): For being an infamous assassin and a member of Baroque Works; Life sentence, Level 4.
 * Bentham (Mr. 2 Bon Kurei): For being a member of Baroque Works; Life sentence, Level 3, Prisoner number C9915; Currently residing in Level 5.5
 * Galdino (Mr. 3): For being a member of Baroque Works; Life sentence, Level 2, Prisoner number D0464; Currently wandering in Level 5.
 * Portgas D. Ace: For being a member of Whitebeard Pirates and piracy; Death penalty in less than 16 hours, possibly Level 5.
 * Jinbei: For causing an uproar at Marine Headquarters and refusing to fight on behalf of the World Government; Temporarily sentenced, possibly Level 5.
 * Buggy the Clown: For piracy; Level 1, Prisoner number E8200; Currently wandering in Level 5.
 * Emporio Ivankov: Reason unknown; Level 5; Currently residing in Level 5.5.
 * 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; Currently receiving treatment in Level 5.5.
 * Inazuma: Reason unknown; Level unknown; Currently residing in Level 5.5
 * 3 Giants: Reason unknown; possibly Level 5
 * Roche Tomson: Reason unknown; Level 5.
 * 500 pirates captured by Admiral Kizaru (Awaiting transfer)

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

Sir 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).

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.

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.

Jinbei has 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 sign in folding.

During the Sabaody Archipelago incident, Kizaru captured 500 pirates, and all of them are currently being transferred into Impel Down.

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.

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.

Roche Tomson is one of the Level 5 prisoners listed on the list Mr. 2 Bon Kurei (disguised as Hannyabal) was reading from.

After Monkey D. Luffy's loss to Magellan, he was coated in the lethal poison of the Hydra, which will 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 is being healed in Level 5.5.

Trivia

 * 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.
 * 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.
 * According to Sengoku, only one prisoner has ever escaped from Impel Down; Kinjishi the Flying Pirate escaped 20 years prior to the present storyline. However, Sengoku blames the escape on the Marines' mistakes. Since then, no one has escaped, let alone infiltrated, Impel Down before Luffy.