Water Wall
I’ve worked in a number of buildings that had water flowing down a plexiglass wall into a pool at the bottom, into which people would toss coins. As delightful as the sound is, I can’t help but imagine how difficult it must be to keep that water clean. Because you just know if people are tossing their germ-laden coins into the pool, the little tykes they tow along with them are spitting into it.
Unless, of course, I’m just cynical.