In the Black Hills of South Dakota, four of America’s past presidents watch over their country. Carved into the granite face of South Dakota’s mountainous landscape are the faces of George Washington, Thomas Jefferson, Theodore Roosevelt, and Abraham Lincoln. Each head is approximately 60 feet tall. The sculpture was made to represent the first 150 years of American history. Mount Rushmore is a national monument that welcomes over 3 million visitors each year. (STEFANO SALVETTI—GETTY IMAGES)