San Giorgio Maggiore, Venice
The optical illusions of the basilica's floor is made up of just 2 different tiles shapes and although perfectly repetitive in plan, their combined effect creates sweeping curves, shifting geometrical shapes and an apparently undulating floor surface which appears to alter wherever one stands. The optical effects created by walking across this floor induce the feeling that one is walking into a drawing by M.C.Escher.
From bottom left to top right - rectangles appear with perspective to morph into cubes....
Sadly almost everyone misses this optical illusion because they stare only up at this.