Windblown rock formations in an ancient Roman quarry.

The world's largest key collection features keys to the White House, Frankenstein's castle, and Hitler's bunker.

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

A 16th-century horror show built in a lovely Italian garden.

This whimsical castle of grottoes was the labor of love of a French postman, and one of the greatest achievements of outsider architecture.

One man has carved a number of natural New Mexico caves into psychedelic sandstone temples.

Gleaming self-built castle towers made from beer cans and inspired by "Vitamin Mary Jane."

Sandstone rock formations that look like they belong on the cover of a progressive rock album.

The highest peak in Utah is the hardest to reach, but only if explorers choose the hard way.

See six states, pickled freaks, rocks, and antiques.

The haunted reputation of these abandoned Colorado train tunnels is probably not helped by the terrifying spiked fence.

This Colorado hiking trail provides a small gold mine of abandoned gold mines.

A collection of fading fantasy tchotchkes lines this dirt road in the Colorado wilderness.

One of the largest Buddhist stupas in North America is built of concrete designed to last 1,000 years.

The remains of the dam that unleashed a 15-foot wall of water on Denver.

Seller of surplus nuclear research materials.

Wedding chapel's mysterious spiral staircase said to be miraculously constructed.

This innocuous New Mexico storefront was once the secret jump-off spot for Manhattan Project scientists.

It's not hard to see why the historic Peabody Conservatory of Music's library has been described as a "cathedral of books."

Artistic cabins actually grow deep in the Canadian wilderness.

The childhood home of Henry Jones Jr. is now an adventure-themed bed and breakfast.

If there is one thing you don't want to be in Sweden during Christmas, it's a Yule Goat.

Bring your hiking shoes, wool socks, and thermal underwear for a stay in these cozy forest huts.

This giant boulder is pinched over a 1000-meter abyss by two mountains.