The Mount Rushmore National Memorial is a sculpture carved into the granite face of Mount Rushmore near Keystone, South Dakota, in the United States. Sculpted by Danish-American Gutzon Borglum and his son, Lincoln Borglum, Mount Rushmore features 60-foot sculptures of the heads of four United States presidents: George Washington, Thomas Jefferson, Theodore Roosevelt and Abraham Lincoln. The entire memorial covers 1,278.45 acres and is 5,725 feet above sea level. South Dakota historian Doane Robinson is credited with conceiving the idea of carving the likenesses of famous people into the Black Hills region of South Dakota in order to promote tourism in the region. Robinson's initial idea was to sculpt the Needles; however, Gutzon Borglum rejected the Needles site because of the poor quality of the granite and strong opposition from environmentalists and Native American groups. They settled on the Mount Rushmore location, which also has the advantage of facing southeast for maximum sun exposure. Robinson wanted it to feature western heroes like Lewis and Clark, Red Cloud and Buffalo Bill Cody but Borglum decided the sculpture should have a more national focus, and chose the four presidents whose likenesses would be carved into the mountain. After securing federal funding, construction on the memorial began in 1927, and the presidents' faces were completed between 1934 and 1939. Upon Gutzon Borglum's death in March 1941, his son Lincoln Borglum took over construction. Although the initial concept called for each president to be depicted from head to waist, lack of funding forced construction to end in late October 1941. The U.S. National Park Service took control of the memorial in 1933, while it was still under construction, and has managed the memorial to the present day. It attracts nearly three million people annually. National Treasure 2 might have been a complete fabrication of American history, but Nicolas Cage was right about one thing: there's a secret room hidden away in Keystone, South Dakota's Mount Rushmore.. and it's filled with awesome stuff!