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

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

A celebrity from the late Cretaceous period.

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

A brass plaque dedicated to a convicted cannibal hangs in the National Press Club, and that's not even the craziest part of the story.

A computer bug so primitive it was an actual insect.

This stately mansion, built in 1787 by America's first Secretary of the Navy, is rumored to be one of the most haunted buildings in Washington, DC.

A super-sized promotional trick that is now a D.C. landmark.

An atomic bomb-proof strongbox protects the U.S. Constitution from terrorists and thieves.

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

Largest Roman Catholic church in North America.

Home to a vast and influential collection of Shakespeareana.

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

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

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

The actual model from the original "Star Trek" series is now on display at the National Air and Space Museum.

The famous abolitionist’s preserved estate is one of Washington's finest monuments to its great Black citizens.

The most decorated dog of World War I is preserved in the Smithsonian.

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

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 national park was once a plantation estate.

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.