Mount Rushmore is one of the most iconic sites in the United States.
The sculpture, which features the 60-foot-tall (18m) heads of four United States presidents, is visited by millions of tourists each year.
But the vast majority don’t realize the iconic landmark actually has a secret: a hidden room.
Mount Rushmore was conceived and designed by Gutzon Borglum between 1927 and 1941.
Borglum was concerned that, over time, his work on Mount Rushmore would lose significance, so he planned to add a secret room behind the president’s faces called the ‘Hall of Records’.
The room would contain busts of famous Americans, a list of United States contributions to science, arts and industry; replicas of the country’s constitution, and other important documents stamped on aluminum sheets.
Construction started in July 1938, but the United States government didn’t share his vision, and demanded that he focus on the faces instead.
Unfortunately, Borglum died in 1941 before the work could be completed on the Hall of Records.
The works were scrapped and the sculpture was instead declared complete that same year.
More than 50 years later, in 1998, his dream was finally completed when a repository of records contained in a titanium vault covered by a granite capstone was placed on the floor of the hall entry.
The repository contains panels explaining how Mount Rushmore came to be carved by whom, a short history of the United States, and reasons for selecting the four presidents depicted on the mountain.
Sadly, the room is closed to the public, though what is inside is not too much of a secret anyway.
The closest anyone can get is the ruin-like doorway which recedes several feet into the mountain.