Julian Beever creates pavement drawings that give a false impression of depth and realism. He skews his images so that when viewed from the correct angle, the brain interprets the drawings as three-dimensional. His technique is closely related to Ames rooms: slanted rooms that appear cubic when viewed with one eye from a particular point.
Update: It turns out that some of the images I had attributed to Julian Beever are actually the work of Kurt Wenner, another street artist. I’ve updated the gallery above to give proper credit.