The intricate stonework of Machu Picchu serves as a testament to Incan engineers.

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.

An Italian crevasse filled with abandoned buildings gives visitors a look at the world without humans.

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

A crumbling hospital from the 1850s on Roosevelt Island.

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

A psychedelic labyrinth on the San Francisco bay.

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.

A terrific purveyor of natural history objects and curios.

London's creepiest cemetery was once the site of dueling magicians and mobs of stake-carrying vampire hunters.

Like a kitschy mirage in the Mojave, this eatery serves up classic 50s-style diner meals and a dinosaur sculpture garden.

Crawl through the hole in the middle of this stone to break off a bad relationship or initiate a good one.

This Victorian graveyard in Leeds is a macabre collection of beautiful tombs and memorials.

This complex of vertically-excavated Buddhist, Jain, and Hindu monolithic temples in India's Maharashtra providence illustrates a spirit of tolerance characteristic of ancient India.

Centuries-old bridges grown from tangled roots.

Occult books, tarot, oddities.

The enormous earthwork sculpture honors the ponies that lived and worked in the old colliery.

The name of this ancient Indonesian temple translates as "Elephant Cave" but it could be more accurately called "The Hellmouth."

A sprawling nature preserve harbors the world's only living dragons.

Bali's remote "gateway to heaven" is one of the most sacred places on the island.