An 18th-century townhouse that once hosted guests of the president.

The sculptor was instructed to add “stallion attributes” to the general's bronze mare.

The "Key of Keys" for Washington, D.C. and the apocryphal landing place for the military campaign that started George Washington's career is now at the bottom of a well.

A bas relief commemorates the "Nuns of the Battlefield" who cared for soldiers on both sides of the conflict.

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

One of the last mosaic tile facades found in the city.

A line of blue paint marks the route of the inaugural parade.

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

This sandwich shop has a century-old elevator behind a sheet of plexiglass.

This Masonic lodge was the first major private building to be constructed in Washington, D.C. after the Civil War.

Over the last century, this elegant columned facade has been home to the headquarters of a bank, several nightclubs, and a restaurant.

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

A replica of the famous memorial statue at the Normandy American Cemetery hides in an office building in downtown D.C.

Once home to the largest photo service in the United States.

The National Park Service’s best-kept secret with views that rival any in D.C.

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

The U.S. Fish Commission’s effort to mass produce carp.

On the Fourth of July this area will transform into a Pompeii-like storm of falling embers and ash.

D.C. once had its own tiny rival to the New York Stock Exchange.

Four bald cypress trees in Lafayette Square, across from the White House, mark the southern edge of a 100,000 year old cypress swamp.

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

A library of poems cascade off the branches of this unsuspecting tree.

The world's largest fire hydrant is supposedly tornado-proof.

This psychedelic tromp l'oeil seems to be beckoning drivers to crash into a wall.