Vanish Mario in the Pipe Land

Not to be confused with Skyhigh Pipelands, a course similar to Vanish Mario in the Pipe Land.

Vanish Mario in the Pipe Land is an unused level found in some personalized copies of Super Mario 64. It is usually found in the Fourth Floor of Princess Peach's Castle, but other methods were also found. It is very similar to Wing Mario Over the Rainbow, but using pipes instead of clouds and rainbows.

Description/Geography:
Other than the two main methods of finding the level in Edge of the Mushroom Kingdom or the fourth floor, another method is found by entering the hole under the water that takes you from Vanish Cap Under the Moat if you fall down the pit. Another method is found by entering the Mirror Room with the Vanish cap on and either entering the door or one of the paintings.

The level itself is said to be somewhat similar to Wing Mario Over the Rainbow, but with different methods of traversing thanks to having different power-ups in use. Most of the pipes are covered like the cannon outside Peach's Castle, requiring the player to get the Vanish Cap to get into the pipes, and traverse around the stage until the star is collected.

Missions:
The most commonly reported missions found in Vanish Mario in the Pipe Land is a secrets mission, where the player must touch 5 crystals found on 5 platforms, and find the star on the largest pipe. Another commonly reported mission is finding 8 red coins spread around the level, and the star spawns on a sub-area near a sideways pipe. The final most commonly reported mission is killing 5 giant Piranha Plants, similar to the same missions found in Tiny-Huge Island. Some players have even said that Petey Piranha, a giant Piranha Plant boss introduced in Super Mario Sunshine, replaced the 5 other plants as a boss fight, but the fight is said to be just a retextured Whomp King fight where Petey tries to fall on you. The players also said that Petey's dialogue was Japanese placeholder text, suggesting the developers didn't have time to complete the fight.

Theorizing:
With the existence of both this stage and Metal Mario in the Depths, many believe that every cap powerup in the game was going to have a second level entirely focused on its use through the level. It is unclear why the two levels were removed with some suggesting that the boss fights encountered by players was supposed to be the main mission for both stages, and that the developers didn't have enough time to complete them. Another theory even suggested that one of the pipes here could've been used to unlock Luigi, and the level was scrapped after Luigi's removal.

Despite not appearing in normal copies of the game, Petey Piranha would appear in Super Mario Sunshine, and some elements of Vanish Mario in the Pipe Land would convert into other Mario games, such as the giant pipes in Supermassive Galaxy in Super Mario Galaxy 2. The idea of entering the mirror room with the Vanish Cap also appeared in the remake of Mario 64, Super Mario 64 DS.