The installation’s official name, “You Who Are Getting Obliterated in the Dancing Swarm of Fireflies,” says it all.

This secluded aqua waterfall in the Grand Canyon is the perfect swimming hole, and the Havasupai tribe's fiercely protected natural wonder.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

An abandoned cemetery lies in ruins as the surrounding forest swallows it whole.

These old stone ruins in the Oregon wilderness were once bathrooms and are steeped in legends of murder.

Remants of foundations, streets, and streetcar tracks inhabit the cliffs where a landslide occurred in 1929.

Dramatic river bend surrounds a natural red-rocked pedestal.

An immersive environment that is part haunted house, part choose-your-own-adventure, and part jungle gym.

A 140-year-old castle with underground caves hidden in San Francisco.

An emerald-green grotto just a short trip from Austin.

On the Oregon coast there is a natural hole that seems to be draining the sea.

Most-visited and most-photographed slot canyon in the American Southwest.

Bring your own cardboard to the slippery slopes of concrete hidden in a neighborhood park.

America's most famous museum of medical oddities is home to the remains of Albert Einstein's brain.

World's largest collection of serial killer artwork and other macabre exhibits.

A psychedelic labyrinth on the San Francisco bay.

A peculiar mansion built by the troubled heir to the Winchester Rifle Company fortune.

Built in 1785, this residence is the oldest stone house in Georgia.

A provocative museum dedicated to the genre and the harsh realities that inspired its origins.

"Not too many people can say they've had a nuclear bomb dropped on them, not too many would want to." — Walter Gregg.

This set of rickety spaceships are prepared to give alien travelers a place to relax and go to the bathroom.

A mysterious inscription may hold a clue about the "Lost Colony" of Roanoke.

Death comes to anyone who dares to touch this concrete column.

An abandoned railroad tunnel forgotten by time awaits inquisitive hikers.