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

A church of bones, decorated with 40,000 human skeletons.

France's most famous cemetery, with some of its most curious tombs.

This shop and gallery is a modern-day cabinet of curiosities, unassumingly positioned along an urban thoroughfare.

Dramatic river bend surrounds a natural red-rocked pedestal.

Dodge prohibitionists and slide through the telephone booth in Crif Dogs.

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

These fantastically named natural pools look like something out of a Scottish myth.

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

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

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

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

A snapshot of the city's fascinating voodoo culture.

This jaw-dropping 19th-century bridge uses its reflection to form what appears to be a perfect circle.

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

The sound of swaying stalks in this stunning grove has been named a governmentally recognized sound.

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

An exquisite tunnel of cascading flowers.

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

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

A crumbling hospital from the 1850s on Roosevelt Island.

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

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

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