For decades, this waterfall remained hidden because of an artificial dam.

Abandoned since the 1950s, the streetcar lane beneath the heavily trafficked bridge lays empty and unused.

The ruins of the suspension bridge hang over Kingsbury Run as a ghost of racial prejudice.

The heroic sled dog of the 1925 serum run is preserved in taxidermy.

This retired stagecoach tavern is the oldest building in Cleveland.

Beneath unsuspecting visitors feet, a capsule containing pieces of America’s civil rights history.

This bridge over D.C.'s Rock Creek Park is sometimes called the "Buffalo Bridge" because of its four buffalo sculptures, which were cast from a single piece of bronze.

A street in front of NASA's D.C. headquarters has been named in honor of the Black women who were essential to early spaceflight.

A historic estate packed with George Washington's heirlooms, and its own nuclear bunker.

The elevator that makes it possible to fly American flags in bulk over the U.S. Capitol

A promising candidate for the lost rock laid by George Washington was unearthed, but the hunt is still on.

Also known as the Founding Church of Scientology.

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

The monument's pointy aluminum tip has been melted down by repeated lightning strikes.

A gorgeous mural outside a beloved D.C. restaurant pays homage to famous Black Americans.

One of the largest artillery pieces in the world sits in a Washington D.C. parking lot.

Members of Congress have traveled between the buildings on Capitol Hill for a century hidden from tourists, press, and storm clouds.

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

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

After his presidency, George Washington planned to live only a few blocks from the Capitol building.

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

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

Home to items never before seen by the public.

This spot memorializes one of the greatest plays in NFL history, unless you happen to be a Raiders fan.