Underworld

The Underworld is the dwelling place of Hades. It is a part of the Olympus Coliseum. It only appears in Kingdom Hearts II. The Underworld consists of two parts, the Cave of the Dead and the Underworld Caverns. The Underworld is also home to the Underdrome where Sora can take part in tournaments. Many bosses are fought in the Underworld, including Demyx, Cerberus, and Hades himself.