The Falkirk Wheel is a very large boat lift that raises vessels up and lowers them down from the Forth Canal to the Clyde canal in Scotland. Read about it here:

The story of The Falkirk Wheel, as well as other engineering feats, is told in the TV series Impossible Engineering on Duke each day at 5.35. Well worth a look, or you can watch the show on demand at TVNZ On Demand. Very interesting.