Amid the sprawling Defense Intelligence Agency Headquarters is one of Washington's least accessible museums.

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

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

A gorgeous mural outside a beloved D.C. restaurant pays homage to famous Black Americans.

The preamble to the U.S. Constitution written entirely from vanity license plates hangs in the Smithsonian museum.

Legend has it that President Grant’s frequent drinking in the lobby gave rise to the term “lobbyist.”

Members of Congress have traveled between the buildings on Capitol Hill for a century hidden from tourists, press, and storm clouds.

Light bulbs, scrap wood, and tinfoil comprise this homemade throne of the gods.

A little marble compass above George Washington's (empty) tomb in the Capitol marks where D.C.'s four quadrants intersect.

The "lovely red Vega" of the legendary record-settling pilot.

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

Washington's iconic carousel has a nice piece of Civil Rights history.

The unique traffic pattern named for an influential urban planner is also known as the Pedestrian Scramble.

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

Decades before the scandal, this staircase on the river was a literal "water gate."

The most accurate timepiece in the world.

D.C.'s first central library was born out of a chance encounter with the philanthropist whose name it bears.

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

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

The hidden offices underneath Memorial Bridge have been locked up since 1976.

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

A hoard of sky catalogs, astrophysical journals, even the works of Galileo and Copernicus.

A celebrity from the late Cretaceous period.

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