Suspense | The Secret Room Inside Mount Rushmore

The sculpture, which famously depicts four former US Presidents as 60 foot granite faces, was constructed between 1927 and 1941 under the direction of architect Gutzon Borglum.Everybody knows that.

But few people know about the secret project Borglum was working on as part of the monument.Over the next 16 years, Borglum wrestled with the federal government about funding and control of Mount Rushmore - which he never technically completed.

Borglum wanted to carve the presidents down to their waists and chisel a description of the memorial next to them. But when it became clear there wasn't enough space for an inscription, he came up with a new idea.He envisioned a grand hall measuring 80′ tall x 100′ long, accessible via an 800-foot granite staircase, that would include busts of famous Americans, as well as bronze and glass cabinets containing historical documents like the Constitution, Bill of Rights and Declaration of Independence.

A massive bronze eagle with a 38-foot wingspan would be mounted above the entrance, with the inscription reading The Hall of Records above the door.

Borglum believed that future generations might find Mount Rushmore as much a mystery as Stonehenge or the Pyramids of Egypt. So he wanted to come up with a way to preserve its history and make sure the story behind the carving would never be forgotten.

The vault was to be built just behind Abraham Lincoln's hairline and would contain all the information anyone would ever need about the mountain. Eventually funding had run out and the project was declared finished on October 31, 1941Finally, in 1998, officials agreed to a scaled-back version of the idea.

Today, sculpted into a series of porcelain enamel panels, is the story and history of Mount Rushmore; along with an explanation of why Washington, Jefferson, Roosevelt, and Lincoln were chosen. There are also panels sculpted with the text of the US Constitution, the Bill of Rights, the Declaration of Independence, and the Gettysburg Address. Park officials even included a biography of Borglum. They're all kept inside a titanium vault behind a giant, 1,200-pound granite slab.

Now, even high-ranking officials are banned from seeing this hidden, and largely unknown, chamber. But its true intent was to serve as a historical record for future civilizations, so we can imagine that Borglum would be pleased to know his project was finally completed - and may one day do exactly as he intended.

Let's find out why.