This little brick tunnel built by Confederate forces was used to conduct surprise attacks on the railroad.

The trials and tribulations of marking Poe's grave.

Rediscovered after a century, the father of the American Navy was reinterred in something dredged up from Davy Jones' Locker.

This pun was simply waiting to come to life, and one defense contractor made it so.

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

Where pardoned turkeys once spent their all-too-brief final days.

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

A secretive collection featuring objects that were designed specifically for U.S. intelligence operations.

The only Civil War battle in Washington D.C. took place near this highest natural point in the city.

A haunting tribute to pioneering photographer Clover Adams.

The actual model from the original "Star Trek" series is now on display at the National Air and Space Museum.

The "lovely red Vega" of the legendary record-settling pilot.

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

This sandwich shop has a century-old elevator behind a sheet of plexiglass.

A much-maligned monument to teetotalism.

The unique traffic pattern named for an influential urban planner is also known as the Pedestrian Scramble.

The country's oldest continually-operated mini golf course lies hidden in plain sight, eclipsed by one of D.C.'s most popular tourist attractions.

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

The oldest continuously operating fish market in the United States.

The most decorated dog of World War I is preserved in the Smithsonian.

Perhaps the most scandalous statue of America's first president.

Legend has it that President Grant’s frequent drinking in the lobby gave rise to the term “lobbyist.”

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

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