A gas station has taken the place of the home of the 19th American President.

A slab of sandstone covered with mysterious 1,000-year-old rock carvings from a vanished North American culture.

Decades before the scandal, this staircase on the river was a literal "water gate."

An overlooked memorial honoring the local Washington residents who died in World War I.

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

There’s a hidden military meme engraved on the World War II Memorial.

The walls of the iconic dome are hollow and have a secret stairway.

Those with a sharp eye can find the hidden image of a German Shepherd on the memorial's Mural Wall.

Inspired by a foil-wrapped potato, (seriously) the Markel Building has been deemed one of the 10 ugliest buildings in the world.

The iconic statue was moved to a new spot overlooking the James river after several years as a mascot for the local baseball team.

Late at night, the bust of the "Dracula" actor was snuck onto the facade of this Budapest castle.

A series of caves under Castle Hill that once held the prisoner Vlad Tepes, better known as Count Dracula.

All of Chicago's wood-paved streets are long gone but two alleys remain.

G.V. Black, the Father of Modern Dentistry, keeps an eternal eye on Chicagoan’s teeth from his perch in Lincoln Park.

You have to love a museum with a truly dedicated focus. A focus on Superman, for example.

These pretty kitties killed and ate as many as 135 railway workers.

Endless rows of boxes of paper records line the hallways of the archaic federal facility where guns are traced.

‘Bush the old fire dog died of poison July 5th, 1869. RIP.’

With over 100 jam-packed rooms to explore plus elaborate tea services and events, the Mansion on O Street is a hidden treasure.

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

Fascinating museum dedicated to the under-appreciated medical history of urology features some wince-inducing devices.

One of the oldest anatomical theaters in the U.S. still in use was once the site of an infamous cadaver riot.

Eighteen miniature death-scene dioramas.

This stone is a marker of one millionaire's personal vendetta against gravity.