1. No water in Hoover Dam
Found in: Colorado River Est., Black Canyon. Cost: $760 million to build, inflation adjusted. Occasionally, you have to see something from a different perspective in order to truly appreciate its size. This is the rear of the Hoover Dam, unobscured by water to reveal its actual dimensions. The dam represents one of the greatest engineering achievements in history.
Hoover Dam Dry
Situated in Colorado’s Black Canyon, the Hoover Dam was constructed in the 1930s. With walls as thick as 660 feet at its base, the concrete building is 1,244 feet long and 726 feet high. Even at the summit, the walls remain a remarkable 45 feet thick.