More familiar than the city of Keystone is its most famous landmark, the Mount Rushmore National Memorial. The over-5000-foot tall mountain features the busts of four former United States Presidents—George Washington, Thomas Jefferson, Abraham Lincoln and Theodore Roosevelt—carved into its face. Thousands of visitors are attracted to the area each year to view this symbol of American government. Located in the Black Hills of South Dakota, Keystone was also a former mining town. Today, an old gold mine, known as Big Thunder, offers tours daily. Several natural underground caves also exist near Keystone, with guided tours available through them. Hiking and horseback riding are also popular activities in the area, with several guest ranches and campgrounds to serve the needs of these visitors. Keystone also retains some of its frontier heritage, with historic store fronts and wild west shows in the Red Garter Saloon.