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

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

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

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

A treasure trove of artifacts, books, and artwork from the "golden age" of exploration.

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

Tucked in the back of this amazing antique store is an important piece of medical history.

A crumbling hospital from the 1850s on Roosevelt Island.

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

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.

A tiny museum housed in a New York freight elevator specializes in the "overlooked, dismissed, or ignored."

A psychedelic labyrinth on the San Francisco bay.

Rippling sand dunes frozen in the Arizona rock.

This iconic L.A. bookshop is housed in an abandoned bank—both symbolic and chic.

Non-profit time travel mart sells goods you would need for a trip through the fourth dimension.

An artsy hidden staircase leads to breathtaking views of San Francisco.

A huge musical instrument played by the ocean.

A beautiful and abandoned New York subway station from 1904, complete with chandelier.

The now-public home of a renowned art collector is full of unique pieces from viceregal and 19th-century Mexico.

This ancient structure was built by a mysterious civilization that was largely destroyed by a volcanic eruption.

This foreboding building was the headquarters of the terrifying Spanish Inquisition in Mexico.

A small pack of an ancient, hairless breed of dog once believed to guide souls through the underworld lives on its grounds.

This colossal ancient sculpture of the monstrous Aztec rain god has a literally stormy history.