At "Aqualand" near Cadiz, you can admire this incredible fountain that seems a Magical Tap floating in the sky while delivering an endless supply of water. It seems a Photoshopped picture but it's not. It is real, just a clever idea that makes possible this optical illusion. Actually there is a hidden pipe inside of the water jet that functions both as a support for the whole structure and to supply the water.
A reader have pointed out that there is another version of the same optical illusion in the Technorama science park in Zurich: