The Falkirk Wheel

The Falkirk Wheel is an incredible piece of design and engineering, linking the Forth & Clyde and Union canals in central Scotland, and allowing boats to travel more than 100 feet vertically between them.

The design of the Wheel is extremely energy efficient; its two 'gondolas' balance each other as one boat rises and the other falls, meaning only minimal power is required:

“...lifting 330 tons (over 80,000 gallons) of water and its cargo in one 7-minute movement, for no more electricity than that required to boil eight kettles of water.”

There's a timelapse video here, and a very detailed explanation in this PDF from Elevator-World.com.