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

Part of a WWII submarine is lurking outside the Washington Navy Yard parking lot.

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

Once forgotten and built over, this historic Black cemetery now houses a poignant memorial.

This simple stone memorial remembers a secret, Geneva Convention-defying interrogation base from WWII.

This lovely picnic spot featuring thunderous jet landings is an aircraft spotter’s dream.

The Pentagon is so large that it was planned like a city, complete with internal highway infrastructure.

Rumor has it the hot dog stand was targeted by two Russian nuclear missiles.

At 207 feet, one of the world's longest continuous escalators.

The romance of early commercial flight still fills this Art Deco destination.

The final resting place of an unidentified revolutionary soldier sits behind a Virginia church.

America's first federal monument.

This grave marks the passing of a historic Jane Doe whose identity remains a mystery to this day.

The narrowest house in America is seven feet of pure spite.

This rare triple-jurisdiction drawbridge passes through Virginia, Maryland, and Washington, D.C.

An original apothecary from 1792.

A former major munitions plant that has been converted into a sprawling art space.

The only place for a truly presidential dram.

This stately building in Alexandria, Virginia was built by Freemasons to honor one of their most famous members.

This statue of one of baseball’s greatest pitchers looks like something out of a sci-fi horror movie.

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

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

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

A layered tribute to the work of mosaicist Isaiah Zagar.