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

A small triangle of DC grass is the final resting place of one of Sonny and Cher's songs.

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

Go take a picture with the inventor of the daguerreotype photographic process.

This robust fence in front of a historic Georgetown home is likely made from hundreds of recycled Revolutionary War firearms.

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

The privately owned cemetery that holds room for Washington's finest when they step down from life.

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

A haunting tribute to pioneering photographer Clover Adams.

Obscure Freemasons still live in D.C.’s largest private residence.

Perhaps the most scandalous statue of America's first president.

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

This imposing Masonic temple a mile from the White House was the first public library in Washington, D.C.

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

A Civil War fort in the middle of Washington, D.C. has been swallowed by a forest.

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.

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

This lonely waterfront memorial to the men of the Titanic was erected by the "Women of America."

People escaping slavery may have hidden inside a corpse vault.

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

The winding route passes through an enclosed alleyway, two tunnels, and leads to the White House basement.

A three-story tower of books about Abraham Lincoln is one of the more unusual monuments to the president.

Fittingly, America's museum of architecture is itself a magnificently designed old building.