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

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

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.

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

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

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

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

Before Nixon, "watergate" meant canals.

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

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

A celebrity from the late Cretaceous period.

Outsider art meets paleontology at this roadside reptile repository.

The last holdout of a pre-Civil War rebel who took the matter of slavery into his own hands.

The semi-reclaimed ruins of this canal were once part of an ambitious plan to reroute the mighty potomac.

At Washington's Dulles Airport is a satellite museum (no pun intended) with three quarters of a million square feet of aircraft history.

I-95's Tijuana-style celebration of kitsch at the Carolina border.

The uniquely-designed winter home and sculpture studio of Anna and Archer Huntington.

The oldest continuously operating fish market in the United States.

They sort through millions of dollars worth of diplomatic gifts on behalf of the government.

A portal into the bricked up canal that runs through the heart of Washington D.C.

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

This mysterious structure by the Washington Monument is a flood barrier designed to protect the White House against rising waters.

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