The Falkirk Wheel and Millennium Link: I saw this on the Discovery Channel the other day. It’s a boat lift in Ireland Scotland (sorry) used to connect two canals that are 110 feet apart vertically. You float your boat into the cradle, and the wheel spins like a big merry-go-round.
Apparently due the cancellation of weight between the upper and lower cradles, it takes almost no effort to move your boat and the thousands of gallons of water it’s sitting in. The pictures don’t do it justice — you really need to watch it in action.