#122 - Illusion Staircase

The endless stairs from Mario 64 aren't actually endless, as Mario is constantly being teleported back. Also, the music playing is known as a Shepard Tone, a sound that is seemingly always increasing in pitch, but it's just notes repeating indefinitely.

SOURCE 1: http://www.suppermariobroth.com/post/145756710755/the-endless-staircase-in-super-mario-64-works-by

SOURCE 2: http://www.charliemccarron.com/2013/06/shepard-tone-illusion-and-the-super-mario-64-endless-staircase/