A monument in Washington D.C. marks the spot from which all other roads were supposed to stem.

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

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

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.

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.

For 60 years, the academy had no permanent location until members voted Washington D.C. as its forever home.

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

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."

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

This lonely waterfront memorial to the men of the Titanic was erected by the "Women of America."

The country's oldest continually-operated mini golf course lies hidden in plain sight, eclipsed by one of D.C.'s most popular tourist attractions.

The oldest continuously operating fish market in the United States.

The only National Monument ever to go missing for nearly 50 years then resurface in a dump.

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

The national park was once a plantation estate.

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.

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

The rogue roots are gradually consuming some of the historic marble grave markers.

The semi-reclaimed ruins of this canal were once part of an ambitious plan to reroute the mighty potomac.

The last holdout of a pre-Civil War rebel who took the matter of slavery into his own hands.