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.

An ear-piercing buzzer calls lawmakers to a vote with a series of long and short rings to form coded messages.

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

Bar full of oddities, specimens, artifacts and homages to the great dime museums of the past.

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

The national park was once a plantation estate.

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

This isn't your average roadway—it's actually a National Park and a transportation pioneer.

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

The oldest continuously operating fish market in the United States.

The discovery site of the "Capitalsaurus," the official dinosaur of Washington, D.C.

This lovely pocket park is one of the most under appreciated in D.C.

A historic neighborhood church is reborn as a psychedelic arts collective.

A super-sized promotional trick that is now a D.C. landmark.

This lonely waterfront memorial to the men of the Titanic was erected by the "Women of America."

The privately owned cemetery that holds room for Washington's finest when they step down from life.