Senators used to relax in the nearly forgotten marble tubs now hidden in the U.S. Capitol Building's basement.

The little-known, 300-year history of the area includes former lives as a bustling tobacco port, parking lot, and industrial dump.

There's an old indoor swimming pool hidden directly underneath the White House Press Briefing Room.

This poor little statue is the most vandalized memorial in Washington.

There's a crumbling old mansion inside the Smithsonian National Zoo.

Seemingly unremarkable items like empty sushi trays, chef hats, and freshness stickers are being preserved so future generations can look back on this beloved cultural import.

People escaping slavery may have hidden inside a corpse vault.

An obscure public service from the U.S. government that redeems burnt, moldy, and soiled old greenbacks.

A computer bug so primitive it was an actual insect.

The house where John Wilkes Booth conspired with his co-conspirators.

The beloved statue at the National Academy of Sciences is oh so inviting to sit on.

This leafy estate is worth $18 million and is so grand it has two mailing addresses.

Franciscan monks created a facsimile of the Holy Land for North Americans who couldn’t afford the trip overseas.

A historic neighborhood church is reborn as a psychedelic arts collective.

There's a 12-foot-tall replica of the Washington Monument hidden under a manhole nearby.

Enormous piles of historically significant stones, dumped by Congress in a forest, and abandoned for 60 years.

One of the dwarven trees dates back to 1625 and survived the Hiroshima bombing.

Long-abandoned trolley tunnels just a mile away from the White House are turning into an art space.

The site of the climactic scene from the classic horror film is now a historic landmark.

Richard III supposedly disposed of his nephews' bodies here in an effort to seal his claim to the throne.

This religious museum resides in a church crypt next to the founder's house.

One of the world's largest collections of pathological specimens.

Public access to clean drinking water was an instant hit among the masses.

An unusual round church in London with a Templar past.