One of the largest artillery pieces in the world sits in a Washington D.C. parking lot.

Amid the sprawling Defense Intelligence Agency Headquarters is one of Washington's least accessible museums.

Government testing at the asylum briefly explored using marijuana as a "truth serum" on Nazi prisoners of war.

A mammoth pair of Civil War artillery guns abandoned out in the forest.

Historic home of America's sweetheart sharpshooter, Annie Oakley.

This 1830s store is believed to be the site of Harriet Tubman's first stand.

Home of the physician who set the leg of John Wilkes Booth after the Lincoln assassination.

The remnants of a wooden-hulled fleet built and abandoned in WWI, now home to a thriving ecosystem.

For nearly a year, General Ulysses S. Grant was based here during the American Civil War.

Taste the white whiskey that the United States' first president once distilled and enjoyed.

Bubbling up from deep underground is the warm crystal clear water that fills the Warm Springs Pools, America's oldest spa.

The largest cemetery for enslaved people in Loudoun County was almost lost to history, if not for the research of a minister.

An overgrown garden stands as a grim marker of an unrealized dream.

A highway marker that honors a former spy plane pilot and local hero.

The most historic church in Fairfax County played a role in the creation of the American Red Cross.

This former Cold War missile control site played an important role in the creation of GPS.

One of the oldest train stations still standing in Virginia played a vital role during the Civil War.

Standing for over 200 years, the abandoned home of a Revolutionary War hero and later a succession of prison superintendents.

Burke’s oldest cemetery also houses the victim of the county's grisliest murder.

The birthplace of Appalachia's only first lady, who some have dubbed the United States' "first female president."

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

The airport was once a Civil War battleground, and the earthwork defenses can still be seen today.

America's second-oldest brick baseball stadium was home to a legendary WWII series that only sailors got to see.

This cannonball stands as a reminder of the final act of a fleeting governor amidst a revolution.