Waterfall: This is one of M.C. Escher's marvelous impossible structures (drawn in 1961) and one of the rare moments to witness water running uphill.
The basis of the illusion is the inclusion of the impossible triangle or tri-bar, developed by Roger Penrose.
In this image of a perpetuum mobile, a self-sustaining waterfall, the water runns uphill and the two towers are the same height despite the fact that one has more levels than the other.
It is a trick to see a reality that is not there!!!