The Olympus Coliseum

The Coliseum is protected by Hercules and antagonized by Hades. Sora is able to train here and can compete in various tournaments. Olympus Coliseum is one of the smallest worlds, consisting of only the main entrance, a lobby and the coliseum itself. It does, however, have a keyhole, hidden beneath a large block in the lobby. Because of the popularity of Hades, the Underworld was added to the sequel. The Underworld consists of its own "lobby" which is one boat ride across the river Styx to the Underdrome, the Underworld's equivalent to the Coliseum, the "Lost Road" to an alcove containing a lock used to seal the Underdrome, and the Cave of the Dead which leads to Hades' temple. All of these Underworld areas are infested with Heartless, as well as mysterious white puffs of smoke which can be souls of people who died.