Volcanic stone sentinels stand watch at a Korean Bell Garden in Virginia.

A total of 14 men held the title of "president" before George Washington—their historical legacies are enshrined in the lobby of a hotel.

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

These hooded graves are the only of their kind in the United States.

A cave on the Maryland border where civilians took refuge during the bloodiest battle of the Civil War.

A renovated schoolhouse that highlights the history of Clarke County's Black community.

A natural spring situated on the grounds of the Hawthorne estate.

This striking Victorian Home with its 113-foot turret is best known as the site where abolitionist John Brown was executed in 1859.

A galaxy of glowworms—larvae of a gnat—hides deep in the belly of these caves.

An abandoned railroad tunnel is now filled with bioluminescent bugs.

You'll need cowboy boots to trek to this old-fashioned saloon nestled in a giant natural cave.

This shop filled with oddities and knick-knacks is named for a 19th-century charlatan.

Endless rows of boxes of paper records line the hallways of the archaic federal facility where guns are traced.

An abandoned 1920s school with a mysterious history.

Despite violent work crews and massive delays this abandoned canal tunnel was built to last into the modern day.

The ruins of this long-abandoned unsuccessful gold mine can still be found.

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

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

The final resting place of the tragic king and queen of the Jazz Age is tucked away in a small Maryland graveyard.

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

Easter in Westminster may be the only time and place to behold Edgar Allen Poe made entirely of Marshmallow Peeps.

An abandoned stretch of highway, deteriorating next to the operational one.

An out-of-place Air Force radar dome is all that denotes this park as a former missile launch site.

A decaying garage hidden amid the dense forest is all that remains of a once-prosperous dairy farm.