Ice-Cold Outpost

Ice-Cold Outpost is an unused level found in some personalized copies of Super Mario 64. It is usually reported to be found in Snowman's Land, and collecting the star here is awarded as a Castle Secret Star. It is described as a vast military base-like setting mixed with elements from the snow courses in the game, with snow filling the outpost on the inside. The theme is interestingly reported to be a remix of the normal snow mountain theme, which is commonly reported to be heard in another anomalous level, Cold, Cold Crevasse in Cool, Cool Mountain.

Description/Geography
There have been multiple reported methods of entering Ice-Cold Outpost. One method simply requires the player to walk past the igloo in Snowman's Land, find a crack in the wall, kick it, and go into the hole left from the kick to enter the level. Another method is through using a Backwards Long Jump to enter the mirror room on the second floor, and entering the Cool, Cool Mountain painting not reflected on the other side. On the other side, the wall takes you to Snowman's Land, but in the mirror room, it will take you to Ice-Cold Outpost. The level itself is described as a snowy military base-like area, filled with Mr. Blizzards, Spindrifts, and Snufits.

Missions
The most commonly reported missions in this level are a red coins star, where the coins are spread throughout the level, finding 5 secrets under military crates, and the final most reported mission is reaching the top of the base, having to traverse past snowballs with similar behavior to the rocks in Hazy Maze Cave, with the star located on a grey platform.

Theorizing
It is unknown why Ice-Cold Outpost was removed, as it seemed to be one of the most completed levels that the AI could manifest. Many believe it could've been removed on accident and there wasn't enough time to add it back in, while others believe it was removed for being overall redundant because of the two snow courses.

Some believe that elements from Ice-Cold Outpost would be implemented into Chief Chilly Challenge in Super Mario 64 DS, such as entering the mirror room to enter the level.