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

The first memorial dedicated solely to the Black troops who fought for the Union.

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.

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

A muscular Art Deco monument represents the struggle between regulators and unbridled markets.

This seemingly out-of-place gas station by the Watergate hotel was once described as the most expensive gas station in the world.

One of the most influential presidents in U.S. history wanted only this plain, elegant monument as his lasting memorial.

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

"Congress may voluntarily remain in session throughout the summer, in order that our Congressmen may be protected from the intolerable discomforts and dangers of the ordinary outdoor weather!”

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

The little-known, 300-year history of the area includes former lives as a bustling tobacco port, parking lot, and industrial dump.

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

Daily lunch spot for many of Washington, D.C.'s cab drivers.

This unique museum cafeteria showcases the history and regional diversity of African American cuisine.

This restaurant has been a haven for D.C.'s LGBTQ community since the 1950s.

The fountains of the U.S. Navy Memorial are annually salted with water from the Seven Seas as part of a nautical ritual.

A tiny monument to the unsuccessful attempt by Thomas Jefferson to place the prime meridian in Washington.

A heroic pigeon that, through a barrage of gunfire, delivered a message that saved over 100 lives in World War I.

Before Nixon, "watergate" meant canals.

Art deco landmark on the outskirts of Washington, D.C.

A much-maligned monument to teetotalism.

This unacceptably tall building was the real reason for Washington, D.C.'s skyscraper ban.

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