Born a slave on the Arlington estate, Parks dug the first graves at Arlington National Cemetery, and was buried there, too.

The story behind the mysterious symbol painted in front of the historic university's famous Rotunda.

The Pentagon is so large that it was planned like a city, complete with internal highway infrastructure.

The system of air guns are fired off remotely to scare any trespassing avians.

The naval commander’s proudest moment in battle is memorialized in this unique tomb at Arlington Cemetery.

Conveniently located within binocular range of a nuclear bunker, the "summer camp" area was a painfully obvious spy house.

This sprawling farm was once a Cold War-era hideaway for the nation's top diplomats.

Hear, smell, see, taste, and touch history at this immersive Civil War hospital.

The Pentagon sits on a former island that was in Virginia at low tide and D.C. at high tide.

The controversial urban planner who designed Washington, D.C., was buried in Maryland, and can presently be found in Virginia.

The tomb was guarded by soldiers from both sides of the war, and some left their initials carved in the brick.

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

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

Please don’t anchor your boat onto the Department of Defense’s underwater data cables.

Located at the former Lorton Prison the Lucy Burns Museum tells the story of the 91 year history of the prison including the dark chapter of its involvement in the women's suffrage movement.

This colonial tavern played host to George Washington, Thomas Jefferson, and other famous early Americans.

The remains of a historic plantation nestled in between a parking lot and the rental car return at Reagan National Airport.

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

The iconic statue was moved to a new spot overlooking the James river after several years as a mascot for the local baseball team.

This simple stone memorial remembers a secret, Geneva Convention-defying interrogation base from WWII.

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

Soldiers were buried next to Lee's house in the center of Arlington Cemetery to dissuade the general from reclaiming his property after the war.

Under a playground is a little-known sealed train tunnel that likely contains the bodies of workers trapped by cave-ins.

The narrowest house in America is seven feet of pure spite.