The latest issue of TIME had an interesting image and caption on 'The floating waterfall' in their Big Ideas category - this is at the Palace of Versailles courtesy a Danish-Icelandic artist. You can see more on the link here.
I have not been to this floating waterfall but I have seen something similar in Dubai at the Miracle Gardens. It seems like the water is pouring out from nothingness in mid-air but if you get close enough, of course, you can see the mechanics behind it and the illusion remains no more. I was thoroughly intrigued by this spectacle and am surprised there aren't many around, or maybe there are and I don't know. Have you been to either of these two water-related sculpture attractions or seen something similar?