One of the oldest standing structures in Montgomery County, Maryland.

The bridge's highly-contested plaque (once again) honors Confederate President Jefferson Davis.

Surrounded by traditional homes, this Tolkien-esque dwelling stands out on a quiet street in suburban Maryland.

The first purpose-built art gallery in the United States is once again open as a center of craft arts.

A historic arena where the Beatles played their first concert in the U.S.

Railroad officials in the early 1900s sought to spare travelers the sight of Roman soldiers’ private parts.

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

An easily overlooked memorial to a Ukrainian famine-genocide that killed over 4 million people.

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

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.

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

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

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

Decades before the scandal, this staircase on the river was a literal "water gate."

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

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

A historic ruin just 20 feet away from a busy highway onramp.

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

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

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

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

A fortified city, home to a remaining population of five families

It took 40 years to build this Eden-like garden in Marrakech, later restored by Yves Saint-Laurent.

Fortune tellers, snake charmers, poets, and storytellers all gather on this historic square in Morocco.