Mount Rushmore's Secret

Mount Rushmore, located in South Dakota, is a national monument that honors four American presidents. Behind the monument is a room that was intended to house important documents and information about the carving of the presidents' faces. However, construction of the room was halted when the government ordered the sculptor to focus on the faces instead. The room now contains 16 porcelain and enamel tablets describing the project and a brief history of the United States. The tablets are kept in a teakwood box and sealed inside a titanium vault, located behind Lincoln's hairline.