Waterfall is a lithograph print by the Dutch artist M.C. Escher which was first printed in October, 1961. It shows an apparent paradox where water from the base of a waterfall appears to run downhill before reaching the top of the waterfall.
Waterfall, Original lithograph print by M.C. Escher
A stylised version of the channel in Waterfall with ambiguous 3-dimensional detail added
While most two-dimensional artists use relative proportions to create an illusion of depth, Escher here and elsewhere uses conflicting proportions to create the visual paradox. Waterfall has the structure of a Penrose triangle, an impossible object designed independently by Roger Penrose and Oscar Reutersvärd.
The image depicts