Corrida Colosseum

The Corrida Colosseum is a colosseum owned by the Donquixote Family that is located somewhere in Dressrosa.

History
This stadium is usually used for hosting fights and competitions. 20 years ago, Kyros was an active fighter and won 3000 fights before disappearing.

At some point, Diamante became the respected and beloved curator of the building, thus earning his title, "Hero of the Colosseum".

Dressrosa Arc
When the Straw Hat Pirates landed on Dressrosa, a competition over the Mera Mera no Mi held by the Donquixote Pirates is about to begin. A lot of gladiators from the Donquixote Family, various countries, factions and pirate crews, including Luffy, for a total of 556 participants, compete for the prize.

Layout
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.

Rules
As a rule laid out by the Donquixote Family, 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.

The Corrida Colosseum tournment is divided in various rounds.

Round 1: Battle Royal
There are some restrictions for those competing in the Battle Royal. 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 want to see blood. Another rule is that alliances in the ring are allowed. However, they are highly disliked, even seen by some as fighting dirty, and as such not encouraged. Falling into the surrounding water means disqualification by ring out, though this does not mean the contestants in question are safe, as the water contains little fighting fishes.

Staff
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.

Round 1: Battle Royal
556 participants got divided into several blocks from A to D, only one winner per block shall pass to the next round. Donquixote Pirates seem to be the only ones able to skip through this round.

Trivia

 * Corrida translates to "race" in Spanish and Portuguese.
 * The Corrida name is a reference to Spanish bullfighting.
 * The layout of Corrida Colosseum is most likely based on the Roman Colosseum, which once held tournaments with gladiators who fought to the death.