Autostereograms, also known as "magic eye" images, are optical illusions that reveal hidden 3D shapes when viewed with the right focus. While most are digital or printed, some artists have created large-scale outdoor sculptures designed to be experienced this way.

One of the most famous is "The Stereogram Wall" in London, featuring a patterned brick surface that reveals a floating cube when viewed correctly. In Tokyo, the "Hidden Dimension" sculpture in Roppongi Hills uses layered metal plates to create a 3D cityscape illusion.

New York's "Magic Eye Park" installation features a series of granite slabs with precisely carved grooves that form a hidden skyline when stared at cross-eyed. These innovative works challenge viewers to engage with public art in an interactive, almost meditative way.

These sculptures push the boundaries of public art by combining traditional craftsmanship with perceptual psychology. They transform ordinary spaces into playgrounds for the mind, inviting passersby to pause and unlock their hidden dimensions.