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

This nine-story building is the oldest standing skyscraper in D.C.

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

The innocent intentions of this monument are somewhat lost in the sculpture's muscled imagery.

The most magical part of this Latin American and Caribbean art museum is a room covered in beautiful blue tiles from floor to ceiling.

The grand marble structure next to the White House is Andrew Carnegie's temple to Pan-American diplomacy.

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

This mysterious structure by the Washington Monument is a flood barrier designed to protect the White House against rising waters.

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

A gift from Japan, 17th-century lantern stands among the cherry trees at D.C.'s Tidal Basin.

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

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

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

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

The Lincoln Memorial has inspired many, even though a word on the inscription appears to be spelled incorrectly.

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

Born a slave on the Arlington estate, Parks dug the first graves at Arlington National Cemetery, and was buried there, too.

An oft-overlooked, magically musical monolith that stands majestically between Arlington Cemetery and the Iwo Jima Memorial.

In what is rumored to be an intentional act of spite, this memorial almost completely obscures the nearby grave of a senior officer.

A gift from Scotland to the United States in memory of the 270 lives lost when Pan Am Flight 103 exploded over Lockerbie due to a terrorist bombing.

Though his role as the inventor of baseball may be up for debate, fans still festoon Doubleday's grave with baseballs.

Recorded as the first person buried in Arlington Cemetery.

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.

The controversial urban planner who designed Washington, D.C., was buried in Maryland, and can presently be found in Virginia.