Falkirk Wheel

The Falkirk Wheel, named after the nearby town of Falkirk in central Scotland, is a rotating boat lift connecting the Forth and Clyde Canal with the Union Canal. The difference in the levels of the two canals at the wheel is 24 metres (79 ft), roughly equivalent to the height of an eight storey building. The structure is located near the Rough Castle Fort and the closest village is Tamfourhill.

This is a brilliant design and seems to be very effecient. Watch the wheel in action in the youtube video below.