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

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

A crumbling hospital from the 1850s on Roosevelt Island.

The sign at the garden gate reads: "These Plants Can Kill."

A lovers' beach, tucked below the surface of the island, provides a safe haven for romance.

Medicinal spa created with the discharge from a geothermal energy plant.

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

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

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

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

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

Rippling sand dunes frozen in the Arizona rock.

A magical place that lets you play in and explore the world of Studio Ghibli.

The macabre collection of Jacques Sirgent, an expert scholar on the undead and all of their trappings.

An exquisite tunnel of cascading flowers.

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

The mysterious, fantastical woodland inspiration for "The Lord of the Rings."

A terrific purveyor of natural history objects and curios.

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

La Monte Young and Marian Zazeela's "Dream House" will immerse you in an ever changing world of sound and light.

This astonishingly geometric cave has inspired everyone from Jules Verne to Pink Floyd.

On Japan's Tashirojima Island, cats are king.

An ossuary built in 1210 to collect bones from the Ospedale Maggiore of Milan.

Charnel house at the foot of Mount Sinai.