Dutch artist M.C. Escher completes the lithograph "Waterfall," which appears to depict the never-ending movement of water. The illusion makes use of the Penrose Triangle, a so-called "impossible object" that seems plausible when viewed 2-dimensionally but can't be replicated in 3 dimensions.
* Official Escher website: @
* "M.C. Escher's Legacy: A Centennial Celebration" (book): @
* Video of reconstructed "Waterfall": @
* "Escher for Real": @
* More about Penrose Triangle: @