An immense cave that has served as an outlaw's treasure trove, an underground dance hall, a nuclear fallout shelter, and much more.

Despite a legend that says this highest peak in Oregon was climbed in high heels, scores of people have died on its slopes.

Housed in a century-old building, this museum's dedicated not just to soft drinks, but to the free enterprise system.

The biggest drug trafficking passage between Mexico and the U.S.

A 315-foot spire jutting out from the Blue Ridge Mountains makes for breathtaking views.

Some islands... they come, they go, especially on Lake Travis.

A free, canine-friendly alternative watering hole near the more famous Barton Springs.

A remnant of the last Ice Age, this lake is surrounded by fascinating rock formations.

This monumental Jesus is often referred to as "Our Milk Carton With Arms."

A collection of huge Pre-Colombian structures in Alabama.

This picturesque cliffside beacon no longer calls to sailors but shines once a year in honor of a famous shipwreck.

Erotic art covers the walls of the largest ancient pleasure palace.

No telescopes, no power, no gift shop: The Observatory of Chichen Itza, one of the world's oldest observatories, takes astronomy back to basics.

Some of the Old West's most notorious outlaws frequented this mining town.

Ghost town with a beer-drinking goat for mayor.

This botanical garden outside Chicago boasts an array of more than 300 varieties of lilacs.

The highest point in Texas is capped by a big silver pyramid.

Home to an endangered salamander, a full moon celebration, and a large spring-fed outdoor swimming pool.

Natural catch-basin rocks covered in thousands of drawings spanning many millennia.

When you visit his grave, be sure to rub the Great Emancipator's nose for good luck.

Steep canyon walls hide a forested oasis in the West Texas desert.

The world-record holder for the longest bridge stretching continuously over water.

A spring-fed pool so deep it's used for scuba diving as well as swimming.

A tourist attraction founded around a slumping cabin.