Beginning of the slide.

The Princess's Secret Slide is a secret area inside of Princess Peach's Castle. It has first appeared in the game Super Mario 64 and later in the Nintendo DS remake Super Mario 64 DS. There are three portraits of Peach and Mario can only enter the one in the right.

In the game, Mario can reach this area by going through the top right door in the main lobby which requires at least a single star for access. Mario must there jump through the ceramic window on the right side with a picture of Princess Peach. When Mario jumps inside, he goes to the area with Blue Coins, regular coins and a single 1-Up Mushroom. Mario is able to obtain a star when he reaches the bottom. He can also receive another star if the secret area is completed below twenty-one seconds. If the player falls he/she returns to the lobby. In the DS version, it's accessed in the character room near the Rec Room, but there are two portraits of Peach. Once again, the player must enter the right. Only Yoshi, Mario, and Luigi can complete the under 21 seconds star due to being the fastest

The course is also accessible in Multiplayer in the DS Version. The end is the best place for fighting.