In Super Mario 64, what is the name of the secret slide minigame course?

In Super Mario 64, the secret slide minigame course is Princess Peach's Secret Slide. It is reached by entering the right-hand stained-glass image of Princess Peach in a castle room behind a one-star door.

The course is a hidden slide rather than one of the game’s fifteen numbered main courses. Mario rides a winding track suspended inside the castle’s secret areas, steering through bends until he reaches the finish platform. Opening the yellow ! Block at the end awards the first Power Star associated with the slide.

The course contains a second Power Star for completing the ride in under 21 seconds. Falling from the track does not normally cost a life, which makes the slide a relatively forgiving place to practise steering and speed. Players sometimes shorten the name to “Peach’s Slide” or “The Princess’s Secret Slide.” Reference works also use “The Princess’s Secret Slide,” while the original game’s sign uses the older “Princess Toadstool” name; these labels refer to the same hidden course.