Grand Coulee dam

The largest concrete structure and power producing facility in the United States is the Grand Coulee Dam in the State of Washington. The dam actually consists of 11,975,521 cubic yards of concrete, and 4 power plants. The Grand Coulee Dam provides 6809 MW of electricity to 11 states, and also provides irrigation for over 500,000 acres of farmland. Work began in 1933, during the Great Depression, with the first water spill over the Grand Coulee Dam occurring on the 1st June, 1942. This enormous structure spans 5,223ft and towers 550ft above the bedrock. This dam is so big, that all of the pyramids of Giza would fit inside the base of this behemoth!