I visited Indianapolis for the first time in 2006, and a friend mentioned that I should visit the Children's Museum there to see the "super cool waterclock".
I took that advice and was glad I did! The water clock is 3 stories tall and amazing. I highly recommend visiting the museum if you have the chance.
After many years of remembering the clock, I decided to try to build one of my own. First I just used regular PVC pipes, zip-tied to a piece of plywood.
Once I had the basic concept working, I bought some clear PVC and some fencing and built what you see here. Not quite as large as the one in Indianapolis, but still pretty cool I think!