Wikipedia Entry:

Julian Beever (born c. 1959) is a British sidewalk chalk artist^[1] who has been creating trompe-l’œil chalk drawings on pavementsurfaces since the mid-1990s. He uses a projection technique called anamorphosis to create the illusion of three dimensions when viewed from the correct angle. He preserves his work in photographs, often positioning a person within the image as if they were interacting with the scene.