A reconstructed medieval gateway that was the magnificent entrance to the capital city dating back to 1037.

340-foot statue built to honour the Heroes of the Soviet Union.

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

The 5.5-mile ring of steel posts around the Capitol Building is one of the largest (and most uniform) of its kind in the world.

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

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

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

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

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

One critic described it as "middle Mussolini, early Ramses, and late Neiman-Marcus." Another called it an architectural "natural disaster."

A 1,100-ton train fell through the floor in 1953. Workers got it patched up in just 72 hours.

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

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

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

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

Before Metro, Washington had a robust streetcar network—and you see the remains of this infrastructure if you know where to look.

Before founding the American Red Cross, Clara Barton had a tremendous humanitarian impact by locating thousands of missing soldiers.

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

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

When it comes to handsignals (and colonialism) rock always beats scissors.

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

Before Nixon, "watergate" meant canals.

One of the largest artillery pieces in the world sits in a Washington D.C. parking lot.

Architecture lovers won’t stop touching the National Gallery's 19.5 degree marble prow.