The Princess's Secret Slide

The Princess's Secret Slide is one of three secret levels in Super Mario 64 and Super Mario 64 DS, where Mario must simply ride a winding slide to the bottom, where two Power Stars can be found at the bottom.

The entrance to the slide is on the first floor, atop the central staircase, and behind the star door labeled "1", meaning it will require 1 Power Star to enter. In the room behind the door are three identical stained glass windows with images of Princess Peach on them. The one on the right is the entrance to the slide. In the DS version, the room is expanded to hold the character doors but the slide itself remains the same and is still accessed via a picture of Peach in the same room. If Mario falls off, he will not lose a life, but will be sent back to the castle lobby, but like other secret levels, the player can lose a life by taking damage until it reaches zero. In this case, the only way to take damage is to jump from the first part of the slide to the second part of the slide, resulting in damage, due to falling from heights.

Star 1
Mario must ride the slide all the way to the bottom and hit the ! Block to collect the Power Star.

Star 2
This second Star will only appear if the player reaches the bottom of the slide in under twenty-one seconds. This Star will appear behind the ! block that contained the first star.

Trivia

 * The tune that plays in the course is a variation of the Bob-omb Battlefield theme (aka, the main theme of the game), as well as Cool, Cool Mountain's music. The music is also remixed in Super Smash Bros. Melee, as well as in Super Mario Galaxy 2 in the Tall Trunk Galaxy level "Tall Trunk's Big Slide", and in the Rolling Coaster Galaxy.
 * When the player completes the slide, instead of coming out where they entered, they will find themselves on the center of the first floor when the player exits a course.
 * Other than Peach's Castle, this is the only area of the game not to have Red Coins.
 * This is the only secret course that contains Blue Coins.