Cool down and fill up after visiting Teotihuacán at this bar and restaurant in a deep, underground cave.

A popular tourist cave with a dark past.

Major tourist destination known for its bubbling mud-pools and hot thermal springs.

Tubing through a cave lit with glowworms is a magical underground experience.

An underground mansion with fruit-bearing trees and grapes growing beneath the surface of central California.

Deadly scalding and one of the largest hot springs in the world.

This electric green sulphur lake in New Zealand looks like a cartoonish radioactive dump site.

The final resting place of New Orleans' most famous voodoo priestess.

The remnants of an archaeological camp stand within Tikal National Park.

Central America's deepest lake is actually a volcanic caldera, surrounded by three volcanoes.

Hidden deep in the Guatemalan jungle is a turquoise paradise of natural pools, caves, and waterfalls.

This subterranean disco dance club in a Cuban cave comes with bright lights and a dark legend.

The remains of this ancient fortress atop a manmade hill look as though they were built into a volcano.

The world's oldest map of the holy land gives us a fragmented glimpse of the layout of biblical nations.

As the Dead Sea continues to deplete, massive sinkholes open along its banks.

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

The remains of a former logging boom town, crumbled away in the forest.

Coastal dunes, site of buried Egyptian movie set and former utopian colony.

A massive volcanic plug is now a protected area that hosts a number of bird species.

A hotel and restaurant serving as the mecca of kitsch.

An alley covered with 20 years of bubble gum.

A historic house in St. Louis was plagued by a series of suicides committed by family members involved in a successful brewery.

The last orange grove of the San Fernando Valley is owned and protected by CSU Northridge.

A sign at the end of the Santa Monica Pier marks the traditional end of the legendary American highway.