Café Wall Illusion

The Café-wall illusion is a shape distortion illusion, which makes straight, parallel lines seem slanted. The name is owed to its discovery, in a public Café in St Michael's Hill (Bristol), by Dr. Richard Gregory.

The cause of the illusion is apparently the alternating bricks (dark and light) in staggered rows, but they must also be surrounded by grey lines.

Café-wall illusion: the horizontal lines seem irregular but they are in fact parallel

A building inspired by the Café-wall illusion