In Falkirk in Scotland, the height difference between The Forth & Clyde Canal and The Union Canal is 24 meters. Rather than taking up a lot of land and inconveniencing canal traveling people with time consuming entries and exits through a series of traditional locks, that only lift you in increments of 5 or 6 meters at the time, a lifting wheel was constructed.
A boat enters at the bottom and another boat enters at the top.
And then the wheel is set in motion.
Soon after you are on your way again at the bottom/top of the wheel and the four minute trip will only have consumed about 1.5 kWh, approximately the energy it takes to boil eight kettles of water.
Would you like to know more?
Falkirk Wheel Official Website.
Falkirk Wheel on Wikipedia.