The Hoover Dam is a concrete arch-gravity dam located on the border between Arizona and Nevada in the United States. It was built between 1931 and 1936 during the Great Depression, and was dedicated on September 30, 1935, by President Franklin D. Roosevelt. The dam was named after President Herbert Hoover.

The Hoover Dam was constructed on the Colorado River to control floods, provide irrigation water, and generate hydroelectric power. At the time of its completion, it was the largest dam in the world, standing at 726 feet tall and 1,244 feet wide. Today, it remains one of the largest dams in the United States.

The Hoover Dam generates power for the states of Nevada, Arizona, and California, providing enough electricity to power more than 1 million homes. It also forms Lake Mead, the largest reservoir in the United States by volume.

Visitors to the Hoover Dam can take a tour of the dam, visit the power plant, and see the spillways and penstocks. The dam also offers breathtaking views of the surrounding desert and mountains. It is a popular tourist destination and a symbol of American ingenuity and determination.