The Ice Spire

The Ice Spire is a supposed level in Super Mario 64. It is described as a linear, tower level similar to Tick Tock Clock, except for the fact that it is made out of ice and lacks many details. The Ice Spire can supposedly be found as a sub-area of the Princess' Secret Toybox level, or the Mirror Room in the second floor of Princess Peach's Castle, reportedly by somehow getting behind the mirror and entering the painting meant to represent Snowman's Land or through some other means.

Description
The Ice Spire is described as a large hollowed-out tower made out of ice with several platforms inside of it. The level would have to be traversed using the Wing Cap, which could be obtained in a multitude of ways, such as platforming up the tower before finding the box, instantly having the Wing Cap upon entering the level, or punching a wall to reveal the Wing Cap box in a similar manner to locating the Whomp's Fortress 1-Up.

The level would have several clones of the unused Cracked Ice object that would be in the center of each platform, and you would have to navigate through the holes after they are broken using the Wing Cap, commonly requiring the player to use the A button while flying with the Wing Cap in order to eventually reach the top of the Ice Spire where the level's Power Star resides. It is believed this level was scrapped (if it was originally planned to be in the game and not created by the Personalization A.I.) due to the obscurity of the A and Wing Cap mechanic making it too hard to play.