Secret chamber behind Mount Rushmore that the public is not allowed to visit

There's certainly something cool and intriguing about a secret chamber, especially in one of the most famous sculptures in the world.

In that, a secret passageway leads to a long-buried city of gold which, as you'd expect, is very much sought after.

But unfortunately, the real-life 70ft passageway carved inside the mountain does not feature such a gold mine, though it does have a rather interesting story attached to it.

The tunnel was first created by sculptor Borglum in what was intended by him to be one of the most important features of the world known monument.

It was supposed to be an important part of US history, actually, with replicas of the country's constitution and other important documents stamped on aluminum sheets.

Borglum called it the Hall of Records, which had intended to boast the motto 'America Marches On' at its entrance.

And while the public are not allowed in it today, Borglum had originally planned to allow them, according to a 1975 National Park Service historical study.

The whole idea of the passageway was for future generations to remember important parts of US history, as explained by John Taliaferro in the 2002 book, Great White Fathers: The Story of the Obsessive Quest to Create Mount Rushmore.

"He wanted it so that thousands of years into the future, people would not just see these heads, but have the manual and all the pieces to reassemble the American civilization — the ideas, the words, the blueprint," he said.

So, what exactly happened to this Hall of Records project, well, World War II happened, unfortunately.

As work to build it had just begun, the world was plunged into another World War, and the project was subsequently canceled.

When World War II ended in 1945, work never continued on the passageway and all that is left to this current day is an empty hallway that leads to absolutely nothing.