The twists and turns of this serpentine maze are over 170 years old.

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

This natural Icelandic fissure allows divers to swim right between two volatile tectonic plates.

The mysterious round rocks of Schooner Gulch.

A tunnel dug through the side of a mountain by hand provides convenient yet death-defying access to a small village in China.

Unexplained bald patches in the landscape grow and recede over time, as though they are somehow alive.

A salty red wasteland in Tanzania is a breeding spot for endangered flamingos.

An ancient capital city that dates back 3,000 years old and harbors many surprises.

Brightly painted boulders scattered throughout the Sinai Desert.

A snowy highland notorious for unexplained aircraft crashes is France's own Bermuda Triangle.

Spring that emits water and fire at the same time is said to have remedial properties, and sparked its own religion.

The subtle interplay of fire and water is hard to ignore at this remote Jamaican spring.

The hottest place on the planet.

270 million year-old forest of stone.

Remote, volcanic island that Darwin, Hooker, and the Royal Navy shaped into a thriving, artificial ecosystem.

Stroll through a wonderland of stupendous moss-covered trees.

The world's first and only natural nuclear reactor.

Bohol's mysterious brown hills.

A fiery crater has been burning in the Karakum Desert since 1971.

The chefs at El Diablo use heat generated by an active volcano to cook the food.

Massive puppet-automaton machines created by French artist collective Machines de l’Ile.

Possibly the most beautiful carillon in the world, set atop Iron Mountain in Florida.

A haunted hill that supposedly defied gravity.