The Natural History Museum in London is famous for its M.C. Escher-like staircases though they are not impossible to negotiate! Had to have a go at this perspective myself. Used a relatively long shutter speed to blur the people, ironically it took several attempts to get enough figures in the scene moving, despite choosing a rainy saturday and a busy museum, everyone kept standing still! The title comes from Escher's 1941 paper called "Regular Division of the Plane with Asymmetric Congruent Polygons", which detailed his mathematical approach to artwork creation.