For those with no fear of heights: a skywalk 4,700 feet up on a Chinese mountain.

The world’s tallest outdoor lift stretches along the stone pillars that inspired the floating mountains in the movie “Avatar.”

The now-abandoned tunnels were built for the transcontinental railroad on the route where the first wagon train entered California.

This angular Dwarven tunnel cuts through a mountainside in Glacier National Park.

This World War II-era bunker is now packed with posters and props from movies and TV shows filmed nearby.

A once-glowing grotto at the bottom of Waikapalae Wet Cave.

Climbing this abandoned railway leads to breathtaking vistas of O‘ahu.

The southernmost point in the United States is a beautiful place to look at but a deadly place to wade in.

A Hawaiian stairway to heaven—that you can't climb.

Watch the newest land on the planet form before your eyes.

What remains of the summer palace of King Kamehameha III.

These picturesque Hawaiian falls are home to a rare species of fish that uses a special sucker to climb up cliffs.

A beach made of semi-precious green sand on the Big Island of Hawai'i.

This ancient stone necropolis is in danger of disappearing.

Concentrated around the Dead Sea, these surprising canyons are filled with coursing water, fish, and even crabs.

This cascade of mineral-rich hot springs and waterfalls is an oasis in the Jordanian desert.

A tunnel of hardened lava along Maui’s famous Road to Hana.

This tiny Hawaiian island is slowly coming back to life after being bombed during naval training exercises.

Once home to over 8,000 exiled Hawaiians suffering from Hansen's Disease.

The island of Lanai in Hawai'i is a paradise for cats and cat lovers.

This beautiful natural train tunnel is said to grant the wishes of visiting lovebirds.

A cooled lava flow from the Haleakalā volcano formed these surreal-looking columnar basalt structures.

Unlike most arches, this geological oddity formed in a volcanic dike.

This volcano rises like a giant anthill from the plains below, with a road spiraling up to the rim.