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

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

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

The rogue roots are gradually consuming some of the historic marble grave markers.

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

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

Before founding the American Red Cross, Clara Barton had a tremendous humanitarian impact by locating thousands of missing soldiers.

Soldiers were buried next to Lee's house in the center of Arlington Cemetery to dissuade the general from reclaiming his property after the war.

America's Most Wanted's set resides in this tribute to the history of crime and punishment.

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

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

The national park was once a plantation estate.

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

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 shelves in the back of this thrift store are devoted to saving, not selling, retro tech.

The longest escalator in the Western Hemisphere takes over three minutes to ride down.

The tallest The Church of Jesus Christ of Latter-day Saints temple in the world soars above the Beltway.

Dogs, cats, horses, monkeys, frogs, and fish are laid to rest at the second-oldest pet cemetery in the U.S.

The final resting place of the tragic king and queen of the Jazz Age is tucked away in a small Maryland graveyard.

This once-palatial plantation may have been the site where a draft of the Declaration of Independence was written.

America's first public mental health facility.

A collection of artifacts from Maryland's maritime past.

Wedged between two sets of row houses is an awkwardly located family graveyard.