I have wondered about this ever since I saw National Treasure 2. Is there really a secret area inside of Mount Rushmore? If so, what's inside? A new video shows what really is in the secret vault.

The appropriately named What's Inside YouTube channel convinced the National Park Service to give them a guided tour. They had to get special permission from the US Department of the Interior. This is known as the Hall of Records.

It's a 76 foot deep tunnel with a stairway that comes out right above George Washington's head as the video reveals. They show the dynamite blasts used to hollow out the Hall of Records area. But, what's inside the Hall of Records?

The answer is a granite capstone which has a titanium box which contains another box which contains plates engraved with the text of the Declaration of Independence, Constitution and other major American documents.

The National Park Service website states that the original idea was to have the actual Declaration of Independence and Constitution placed inside the Hall of Records to preserve the documents for history. The sad fact is that the Hall of Records was never completed so the idea was abandoned.

But, is this granite capstone really all there is? The Rapid City Journal shared a story about how Brad Metzler's Decoded TV show explored conspiracy theories about possible KKK involvement with Mount Rushmore. The truth is out there.

As they mention in the video, the Hall of Records is not open to the public as the National Park Service website states. How neat that this very popular YouTube channel was given a brief sneak peak.

Maybe National Treasure 2 wasn't that far off about mysterious areas inside Mount Rushmore after all.

Enter your number to get our free mobile app

UP NEXT: 18 Most Terrifyingly Haunted Places in Wyoming

More From Montana Talks