Washington's top-secret Cold War-era doomsday communications tower is located in a small neighborhood park.

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

A historic ruin just 20 feet away from a busy highway onramp.

The discovery site of the "Capitalsaurus," the official dinosaur of Washington, D.C.

This unacceptably tall building was the real reason for Washington, D.C.'s skyscraper ban.

The only Civil War battle in Washington D.C. took place near this highest natural point in the city.

Four bald cypress trees in Lafayette Square, across from the White House, mark the southern edge of a 100,000 year old cypress swamp.

The span is crooked and made from two older recycled bridges.

You could be standing at the site of one of D.C.'s most fatal tragedies and not even know it.

The institution is sitting on a goldmine of 21,000 paints, varnishes, pigments, and primers preserved for posterity.

The oldest building in the District of Columbia was preserved because of a mistaken connection to George Washington.

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

This restaurant has been a haven for D.C.'s LGBTQ community since the 1950s.

Cold War intelligence agents monitored communist embassies from an attic in a former pigeon coop.

The first purpose-built art gallery in the United States is once again open as a center of craft arts.

A nostalgic bibliographic gem.

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

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

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

Government testing at the asylum briefly explored using marijuana as a "truth serum" on Nazi prisoners of war.

A 200-year-old bar with a cheeky name claims to have served Edgar Allan Poe his final drink.

This bug-eyed water wheel uses the power of the Sun to clean up Baltimore Harbor.

Waterway populated with abandoned projects, including a submarine.

Final resting place of two dozen New York City harbor ships.