World's first "penitentiary," meant to be humane, drove men insane.

Amid the bustle and noise of the Financial District hides a secluded garden oasis above the city streets.

A collision of human error and natural geothermal pressure created this rainbow-colored geologic wonder.

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

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

A snapshot of the city's fascinating voodoo culture.

The neon signs from Las Vegas' past find their final resting place at this unusual graveyard.

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

Wondrous sandstone hoodoos where Native Americans collected clay for pottery, 9,000 years ago.

A theme park that suffered massive flooding during Katrina was abandoned, and now proves irresistible to trespassing explorers.

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

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

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

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

The only structure left with direct ties to the Salem witchcraft trials of 1692.

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

The remains of an early 1900s dude ranch that operated until the 1970s.

A mental health hospital dating back more than 139 years, now features a museum.

Community owned and operated, this property is home to a diverse set of nudists.

The world's largest carnivore sanctuary is home to over 450 meat-eating rescues.