The Colosseum features a round stage surrounded by water, with four cardinal walkways leading to the stage. There are three levels of seating for the audience all around the Colosseum. On one of the cardinal edges is three monitors for the participants' announcements and presentation.
Outside the arena but still in the building, there is a small pavilion area which has restrooms and a stall selling either souvenirs or concessions.
Underneath the Colosseum is the SMILE Factory, where Mansherry and hundreds of other dwarves are also forced to work at. Also, anyone caught rebelling against the Donquixote Family has been placed inside prisons under the Colosseum, and were given the condition that any fighter who wins 1000 matches earns their freedom—easier said than done, as most barely lasted 100—and any attempt to escape would result in all of their executions.
The Fighters' Preparations Room is where gladiators go to prepare for matches of the colosseum. Aside from firearms it is filled with weapons, armor and a bronze statue of Kyros. It is where Luffy made the "Lucy" persona and first met Cavendish and Rebecca.
As a rule laid out by the Donquixote Pirates, the police and Marines alike cannot enter the Colosseum, even if a criminal is clearly within its walls, rendering their authority null and void so long as the criminal in question has at least one foot inside. Anyone who violates this law will be deemed criminals themselves.
Competitors are not allowed to switch themselves with another person between battles.
The Corrida Colosseum tournament is divided into various rounds.
There are several restrictions for those competing in the battle royale. First, the only weapons not allowed are firearms. Second, there is a limit to how much armor each participant can wear. According to Cavendish, the reason for this restriction is because spectators hope to witness blood. Another regulation is that cooperation in the arena is permitted. However, they are highly disliked to the point that some spectators see it as fighting dirty, and as such are not encouraged. Falling into the surrounding water means disqualification by ring out, though this does not mean the combatants in question are safe, as the water contains little fighting fish.
During the battle for the Mera Mera no Mi, there were four battle royale blocks of around 130 people each, being labeled with the letters A through D. The winner of each block went on to the final round.
In the second and final round, the winners of the four blocks face off in a battle royale against the representatives of the Donquixote Pirates: Diamante, Senor Pink, Dellinger, Lao G, and Machvise. During the fight for the Mera Mera no Mi, the latter four pirates were called away to defend the Toy House and so Diamante was left alone with the block winners. New fighting fish circle around the ring, and are not only much more aggressive, but can also jump up and attack in the air. One of the fish held the chest containing the Mera Mera no Mi, and whoever acquired it first would win the tournament seemingly regardless of how many of their opponents they had defeated.
The Colosseum is managed by gladiator-themed staff and by the toys from the outside. They are taught to maintain order within the establishment, and have no tolerance for shenanigans. Because of that, they are granted the power to disqualify any unruly participants as they see fit.
The announcers are supposed to remain impartial, in order to relay information properly. However, whenever popular (or unpopular) participants make some breakthrough, the announcers, at least Gatz, cannot help but be biased, be it in a positive (cheering for Hack), or negative way (despising Bartolomeo).
During the Battle for Mera Mera no Mi (,Battle for Mera Mera no Mi?) 556 participants were divided into four blocks, lettered A through D. Only one winner per block may pass to the next round.
Originally, the winners of the four blocks would have to fight against the Donquixote Family's representatives. Since Machvise, Senor Pink, Dellinger, and Lao G were not present, Diamante participated in this round. This round determined who would own the Mera Mera no Mi.
This venue is usually used for hosting fights and competitions. Twenty years ago, Kyros was an active fighter who won three thousand fights before retiring.
Ten years ago before Doflamingo became King, the Colosseum battles were not to the death. Doflamingo's thirst for violence changed the traditions, as he tortuously drowned a gladiator for not shedding any blood for the spectators.
At some point, Diamante became the respected and beloved curator of the building, thus earning his title, "Hero of the Colosseum".
When the Straw Hat Pirates landed on Dressrosa, a competition over the Mera Mera no Mi held by the Donquixote Pirates was about to begin. Gladiators from the Donquixote Family, various countries, factions, and pirate crews, including Luffy, for a total of five hundred and fifty six participants, entered to compete for the prize.Bellamy entered the tournament not for the fruit, but was offered a chance to rise in rank within the Donquixote Pirates if he won.
Jesus Burgess, under the alias Mr. Store, won Block A's battle royale, while Bartolomeo won Block B's. Luffy succeeded in winning Block C. However, his alias as "Lucy" started to fall apart, as Chinjao, Cavendish, Bartolomeo, Bellamy, Jean Ango, Diamante, and even Burgess all found out.
The arena sustained extensive damage during Block C's conclusion when Luffy's Gomu Gomu no Thor Elephant Gun sent Chinjao falling headfirst into the ring, splitting it in two in the process. Block D's match was postponed for 15 minutes for repair.
Outside the Colosseum, Vice Admiral Bastille and a battalion of Marines were waiting for the losers to step out, so they could arrest all the criminals. However, to their confusion, not a single competitor from Blocks A and B walked out despite a period of time have passed. As it turns out, all losers (aside Bellamy, being a Donquixote Pirates member) who were supposedly taken in for medical attention were in truth thrown into a pit deep underground, alongside toys.
Any contestants who loses in the tournament is dumped down the trash chute, and transformed into toys by Sugar via her Hobi Hobi no Mi, ordering them to entertain Dressrosa citizens, while memories of their existence are erased as well. Bellamy and Riku Doldo III are two known contestants who were exempted from this treatment, as Bellamy was a member of the Donquixote Family, while Riku was taken back to the palace in chains, in order to maintain the country's hatred for the former king and allowing Doflamingo to remain as a beloved ruler.
As Trafalgar Law was captured by Donquixote Doflamingo right outside of the Colosseum, Luffy swiftly left to chase the two fighting Shichibukai. In an unexpected twist, someone Luffy has long-thought dead has returned and took Luffy's place as contestant "Lucy" to win the Mera Mera no Mi to inherit Ace's will.
Eventually, Rebecca won Block D thanks to her training in evading strikes and Hakuba suddenly awakening and attacking all the other contestants, knocking everyone else out, before falling asleep.
For the final round, Diamante, Lucy, Bartolomeo, Burgess, and Rebecca participated in a five-person battle royale. However, mainly due to Burgess's incredibly destructive attacks, large cracks have started to appear throughout the Colosseum.
Sabo eventually destroys the arena ring himself with his immense strength, exposing the SMILE Factory and retrieving the Mera Mera no Mi.
Sabo would later return to the Colosseum and free the convicted gladiators from their cells.
The layout of Corrida Colosseum is most likely based on the Roman Colosseum, which once held tournaments with gladiators who fought to the death.
Even if Lucy is the 556th registered gladiator, the anime counts only 555 fighters, revealing the Block A to have only 137 participants. Adding to them the manga revealed datas there are 137 fighters in Block A, 138 fighters in Block B, 139 fighters in Block C, 138 fighters in Block D and three disqualified fighters (Spartan, Gambia and Maynard) for a total of 555 fighters. This suggests that a fighter of Block A got disqualified or retired before the start of the match.
In the anime-only gladiators list Maynard is registered under his real name instead of his alias, "Capman".
This list also featured unseen combatants, including Komaking, Miko Miko, CD Miyamo-To, Yosi Takas, Cherry Cherry P Sakuruda, and Rimotaro, all of which are non-canon.