The runoff, over-saturated with calcium carbonate, magnesium and sulphur, has solidified over millennia in the same way that stalactites are formed, creating the illusion of a flow of white water.
The brain cannot fathom how an optical illusion can manifest in real life, rendering it "impossible". Photograph courtesy Meiji University Take for instance the illustration of two L-shaped blocks.
Test your eyesight with a challenging optical illusion that requires you to spot the real owl among soft toys in just 7 ...
A similar thing happened with this real-life illusion in which a plane appeared to be completely still in the air because of the way the viewer was moving around it. But this was called "The ...