Hoover Dam is a huge concrete wall built across the Colorado River between Nevada and Arizona. It holds back the water to make electricity and create giant Lake Mead.
People are amazed by how tall and powerful the dam is, standing higher than a 60-story building. It is a famous feat of engineering that took thousands of workers to build during the 1930s.
The dam is made of enough concrete to build a road across the whole country. Guides take visitors deep inside to see the giant machines that spin to make power.
Rushing water spins huge turbines that light up homes in three different states. It is a clean way to make power using only the force of the river.
A tall bridge next to the dam lets you look down at the whole structure from high above. The view of the deep canyon and blue water is breathtaking.