The oldest building in the District of Columbia was preserved because of a mistaken connection to George Washington.

This robust fence in front of a historic Georgetown home is likely made from hundreds of recycled Revolutionary War firearms.

People escaping slavery may have hidden inside a corpse vault.

The sci-fi villain is a little-known inhabitant of the U.S. capital's largest cathedral.

Risk arrest while partying to fund art.

Sniff the Titan Arum's rotting flesh.

Need a hardcopy of the 50-title Code of Federal Regulations? This is the place.

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.

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

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

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

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

Members of Congress have traveled between the buildings on Capitol Hill for a century hidden from tourists, press, and storm clouds.

Fragments of architectural wonders from around the globe are embedded in the newspaper building's walls.

This museum celebrating the almighty dollar lets visitors literally stand in the shadow of a million bucks.

Four glass boxes hover over 1,000 feet in the air to give visitors an unparalleled view of Chicago.

Sit where JFK proposed to Jackie or where Nixon dined on meatloaf at this storied pub.

The national park was once a plantation estate.

The oldest continuously operating fish market in the United States.

This stunning blue and gold room changed cities twice before becoming part of the Smithsonian.

The site of the climactic scene from the classic horror film is now a historic landmark.

Home to items never before seen by the public.

Remnants of a storybook amusement park hidden behind a strip mall.

The last remains of one of the oldest and largest oak trees in the United States calls this state park home.