Boo's Trembling Tower is the 6th main stage of Super Mario 64 The Green Stars, and is located through a pipe surrounded by Boos in the second overworld. The level is built around a massive haunted tower, which belongs to Big Boo, in the middle of a grassy field inhabited by plenty of ghosts, floating eyes, and other spooky residents. There are also a couple of pools of purple quicksand on the side which include smaller checkered platforms as well as snake blocks.