Olympus Coliseum
Olympus Coliseum is featured in all three of the main Kingdom Hearts games. It is based on Disney's thirty-fifth animated feature, Hercules. 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 in the first Kingdom Hearts, consisting of only the main entrance, a lobby and the coliseum itself; the keyhole of this world is located in the lobby, underneath a heavy pedestal. Because of the popularity of Hades, the Underworld was added to the sequel.[39] In Kingdom Hearts II, Hades opens a portal to the Underworld near the exit of the Coliseum. 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. Anyone who is not resident to the Underworld is afflicted by a curse that drains them of their strength (in Sora's case, he is unable to use his Drive Form); the only known protection from this curse isthe Olympus Stone, a medallion used by the gods. All of these Underworld areas are infested with Heartless, as well as mysterious white puffs of smoke which are, presumably, the spirits of the dead.