Triangle of Insanity

 is an expert track in Bloons Tower Defense 4 Expansion. This track is considerably hard as the Bloons only move around the outside, and that makes the track extremely short. It has three entrances and exits. If this track is completed on Medium or Hard, the supernatural speciality will be unlocked.

Trivia

 * This is one of the three tracks that appear in space, the others being Space Truckin' and Blue Laser.
 * This track is based off the Penrose Triangle.
 * It is the only track that is an Optical Illusion.
 * This is arguably the hardest track due to its short and confusing paths, with the other candidates possibly being Monkeys vs. Bloons, Down The Drain, Bloontonium Lab, Crypt Keeper (with Reverse Mode turned off), Tar Pits, Bloody Puddles and Cursed Mirrors.