This stunning blue and gold room changed cities twice before becoming part of the Smithsonian.

The world's oldest soul food restaurant is also one of its best.

A clone of a cloned tree that was so important it allegedly had its own guards.

Seemingly unremarkable items like empty sushi trays, chef hats, and freshness stickers are being preserved so future generations can look back on this beloved cultural import.

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

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

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

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

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

More than 500 unique and specially designed cases collected by D.C.'s "Harmonica Case Man."

A tiny piece of the Moon is embedded in this stained glass masterpiece.

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

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

The sci-fi villain is a little-known inhabitant of the U.S. capital's largest cathedral.

A cavernous three-story, 43,800-square-foot basement that was forgotten about for 60 years.

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

A brass and marble scale model of the solar system embedded in the concrete.

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

They sort through millions of dollars worth of diplomatic gifts on behalf of the government.

With over 100 jam-packed rooms to explore plus elaborate tea services and events, the Mansion on O Street is a hidden treasure.

The most accurate timepiece in the world.

A painfully obvious spy house sits right across the street from the Russian Embassy.

This unique historical monument features large concrete spheres designed to resemble fallen stars.

Sit where JFK proposed to Jackie or where Nixon dined on meatloaf at this storied pub.