the dilemma presented by the obvious overlap of 2 collimate constructions which stretch out from the spectator into space. Collimate course of trees, railway tracks, or wall structures creating an alleyway are all typical stimulants which look as if they connect with each other in the distance.
ALLEY PROBLEM: “Alley problems appear frequently in optical illusions, with the most popular likely being images of trees lining a driveway.”