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

The oldest continuously operating fish market in the United States.

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

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

While most wind tunnels test scale models, the "Cave of Winds" was large enough for actual airplanes.

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

Home to items never before seen by the public.

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

It was once the base for a series of domestic terror attacks.

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

Was there a small "backpack nuke" hidden in the attic? JFK apparently thought so.

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

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

An overlooked memorial honoring the local Washington residents who died in World War I.

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

The first purpose-built art gallery in the United States is once again open as a center of craft arts.

This unassuming passageway played a key role in one of the most important events in U.S. history.

A derelict bit of infrastructure from the canal that once ran through D.C. is landlocked in the heart of the city.

The story behind this beloved toy—named for Theodore Roosevelt and owned by his grandson—is more complicated than you might guess.

Look closely and you’ll notice that the color changes a third of the way up the tower.

Disks are rolled out onto the south lawn to absorb the impact of Marine One's wheels like giant coffee coasters.

A double agent hid information for the Soviet Union beneath this bridge for more than 20 years.

The skeletal white beams stand as a monument to religious dissent.

The iconic statue was moved to a new spot overlooking the James river after several years as a mascot for the local baseball team.