Grand Coulee Dam, Washington

The legendary Grand Coulee Dam is still one of the largest concrete dams in the world, and the largest single electricity production site in the country, generating 6,809 megawatts of power. It is also the origin of the Columbia Basin Project, where water is pumped above the dam into a series of artificial lakes and rivers to irrigate more than half a million acres of the state. Located on the Columbia River, the dam, completed in 1942, is 550 feet high with a total length of 5,223 feet. Though the dam is sometimes closed to visitors due to security concerns, a laser show projected on the 15 acre spillway has been held during summer months, in the past.