A non-native grove of 241 redwoods in Southern California.

The 7,000-year-old calcium carbonate formation creates a magnificent natural bridge.

This once bustling boomtown hotel is now the hottest spot in Nevada for ghost hunters.

A gothic palace of endless stalagmites and pseudoscorpions waits within one of the world's most beautiful caves.

The highest paved road in North America winds its way up Mount Blue Sky in Colorado to an altitude of 14,130 feet above sea level.

The Los Angeles flood disaster that took 400 lives and ended the career of William Mulholland.

'Cause the fence start shaking, the earth was quaking.

Burping, gurgling geothermal mud pots by the Salton Sea.

This Big Sur waterfall drops 80 feet directly into the Pacific Ocean, and inspired the hillside house up top.

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

Entering this curiosity shop is like stepping into a mad scientist's lab.

An annual celebration of the infamous, unsolved skyjacking.

Orcas on display and in the water.

Rustic natural hot springs in the deciduous rain forest.

The highway's southernmost spot is a beloved local attraction.

The "worst battleship ever built" is enjoying a grand second act, submerged 30 feet in the Gulf of Mexico.

The only Florida state park with publicly accessible caves.

A waterfall 600 ft. inside a mountain, once the bane of gold miners, is now a spectacle of nature.

A gargantuan crystal kingdom.

Take a dip beneath the stalactites in this amazing cenote.

One of the world’s largest cave systems houses legends, concerts, and wondrous rock formations alike.

This seaside production studio was built to film 'Titanic' and has been the wet set of choice for other Hollywood productions since.

The development of this cliffside waterpark is representative of Mexico's history of co-op tourism developments.

Inside this mountain lies several kilometers of breathtaking caves.