Hikers can still stroll beneath the long conveyer of this abandoned mining facility hidden in a West Virginia river gorge.

One day a year it is legal to jump off of this astoundingly tall bridge that spans an Appalachian gorge.

Once connected to the outside world by a single train track, this ghost town is looked after by the National Park Service.

An abandoned theme park with a strange and tumultuous past.

Prehistoric animals decorate this popular outdoor park.

The secret city built by the Manhattan Project.

Forget Hollywood, one of the biggest stars in the world can be found in Roanoke, Virginia.

An overgrown collection of miniature buildings still stand as evidence of one couple's obsession with The King.

At Washington's Dulles Airport is a satellite museum (no pun intended) with three quarters of a million square feet of aircraft history.

Burke’s oldest cemetery also houses the victim of the county's grisliest murder.

A spectacular tribute to statesman and philanthropist Andrew Mellon.

Architecture lovers won’t stop touching the National Gallery's 19.5 degree marble prow.

"Congress may voluntarily remain in session throughout the summer, in order that our Congressmen may be protected from the intolerable discomforts and dangers of the ordinary outdoor weather!”

A hidden gem on the lawn of the U.S. Capitol Building designed by landscape architect Frederick Law Olmsted.

A celebrity from the late Cretaceous period.

The "lovely red Vega" of the legendary record-settling pilot.

Daredevil repair workers can worm their way out the access hatch, loop ropes over the apex and rappel down the monument.

Home to the organ played at General MacArthur's funeral.

Look closely and you’ll notice that the color changes a third of the way up the tower.

A cavernous three-story, 43,800-square-foot basement that was forgotten about for 60 years.

A double agent hid information for the Soviet Union beneath this bridge for more than 20 years.

An authentic replica of an Asian temple and garden hidden amongst the natural beauty of Hawai'i.

Once the site of the Hawaiian monarchy, this building was originally designed as a palace.

This once-palatial plantation may have been the site where a draft of the Declaration of Independence was written.