This cardboard sculpture by Koukichi Sugihara of the Meiji Institute for Advanced Study of Mathematical Sciences in Japan won the first prize at the 2010 Illusion of the Year competition. The illusion shown is all the more remarkable in that it is a solid object whereas most entries were computer-generated. See the top ten finalists from the competition, and marvel at what your brain will make you see. Which one do you like best?
[via The Loom]