Princess Peach's Castle/Basement

The basement is the second floor of Princess Peach's Castle you gain access to in Super Mario 64, unlocked after beating Bowser in the Dark World. It contains Hazy Maze Cave, Lethal Lava Land, Shifting Sand Land, Dire, Dire Docks, and Bowser in the Fire Sea. You can also access the pillars required to drain the moat of the Castle Grounds and access Vanish Cap Under the Moat. It contains the first star given by a toad, as well as the encounters with MIPS the Rabbit.

Wario Apparition
Main Article: Wario Apparition

Floating MIPS
Main Aritcle: Floating MIPS

Quin
Main Article: Quin

Castle Dungeon
Main Article: Castle Dungeon