A popular tourist cave with a dark past.

Its dark depths conceal millions of rare, delicate crystal formations.

One of the oldest reform schools in the United States, home to wayward boys such as Merle Haggard, now abandoned.

The California capital city once stood 10 feet lower than it does today.

The last of a gourmet supermarket chain, this store helped spark California's Food Revolution.

This museum looks at the history of one of America's most famous prisons and most beloved albums.

One of the world's tallest Ferris wheels takes visitors high above Las Vegas in a spinning party room.

A giant open-air sculpture made of over 200 full-sized boats.

These banned cigarette vending machines now sell little pieces of pocket-sized art.

An ode to the friendship between four Pacific Rim countries.

Not truly a ship nor a building, the Navy's first and last "landship" is now abandoned due to clerical issues.

An inconspicuous footbridge beloved by San Diego locals.

A couple turned their front yard into an artistic masterpiece.

A Wild West jailhouse that slid down the mountainside.

Inside this store, a mysterious statue draws visitors from the world over.

Once the product of an inexplicable gold strike, this ghost town is now home to one man and his love of classic machines.

Ninety feet off the valley floor is an ancient dwelling put under protection of the U.S. government by Teddy Roosevelt.

A spiritual vortex among the red rocks in Sedona.

This 4,000-foot-diameter hole is touted as "the most well known, best preserved meteorite crater on Earth."

This Route 66 classic sports a giant fiberglass rabbit that you can ride.

See massive fossils that are over 200 million years old in northeastern Arizona.

A clear blue swimming hole with hidden caves, still unexplored.

If drivers cross the rumble strip on this stretch of Route 66 at just the right speed it plays "America the Beautiful."

It's easy to see why this eclectic architectural wonder has been dubbed the "Spaceship House."