A toxic ghost town sitting atop a massive coal fire.

Stroll through a wonderland of stupendous moss-covered trees.

Rippling sand dunes frozen in the Arizona rock.

Eons ago, a rushing lava river formed this pristine passage through solid rock.

A volcanic fissure over two miles long and up to 70 feet deep.

Once strictly off-limits, this lower level housing curious and priceless vehicles of the Petersen Automotive Museum is now open to the public.

Rare collectibles from automated musical instruments to 250 unique automobiles.

A trash dump made beautiful by nature's power.

Staircase winds down the side of Telegraph Hill through gardens, wild parrots flying overhead.

A museum befitting the city responsible for supplying the majority of the world's LSD.

A sculpture made of 10 Cadillacs as a monument to the "Golden Age" of the American automobile.

Abandoned railroad tunnel is home to a colony of three million Mexican free-tail bats.

Trails through lava-carved tube-caves display sparkling bacteria and a rich history.

Massive crater in central Oregon.

The longest continuous lava tube in Oregon.

A cave interior in the shape of the ancient rhinoceros, created by lava cooling around its carcass.

Tour the original street level of Port Angeles, buried underground in 1914.

A bike being "eaten" by a tree is the real Vashon legend behind popular children's book, "Red Ranger Came Calling."

Unique Michigan homes look like something out of Tolkien's "The Lord of the Rings."

An extraordinary mixture of natural beauty and man-made phenomena.

At the "Garage Mahal" in Houston, car culture is about more than just driving.

The magic's in the hole!

This freshwater spring fills with 10,000 gallons of water per minute.

A river with some unusual, and occasionally dangerous, habits.