Planet Zebes

From Zelda Wiki.org

Planet Zebes is a location from the Metroid series that appears as a stage in Super Smash Bros. It is the main setting of Metroid and Super Metroid. The stage is filled with lava that prevents players from falling to their deaths, but also damages them. The lava occasionally rises above the lower platforms, forcing players to jump to the higher platforms. Zebes has not appeared as a stage in any other Smash Bros. game, but locations within it, such as Brinstar, Brinstar Depths, and Norfair, have appeared in the sequels.