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

A unique set of caves that spits waves back out into the ocean.

The only royal palace on U.S. soil has been a territorial capitol, a military headquarters, and a prison for a queen.

Take shelter from Hawai'i's tropical heat under the massive canopy of largest Banyan tree on the island.

A series of waterfalls and pools that flow through the 'Ohe'o Gulch and into the ocean.

This natural marble cave is one of only five national monuments in Oregon.

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

These memorials built by an eccentric bachelor on the side of Interstate 5 cause both wonder and traffic accidents.

This famous bridge twisted itself into oblivion, but not for the reason you might think.

"The Reptile Man's" very own roadside zoo features an albino alligator.

Cave carved out of a huge snow drift collapsed killing one and injuring five in July 2015.

An enormous pink granite batholith, long attributed with spiritual powers by the Tonkawa Indians.

Craggy concrete faces are hidden in the walls of this artificial cave along the San Antonio River.

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

A Wild West jailhouse that slid down the mountainside.

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

This church on a Tohono O'Odham reservation has stood since 1797.

The world's largest military aircraft cemetery.

Some of the tallest ancient American ruins continue to inspire awe and curiosity.

Nevada's largest cactus collection stands outside a candy mogul's small factory.

The final resting place of one of the most sensational guitar players of all time was created only after his father got the rights to his music.

Four abandoned towers hidden above the Douglas fir forest in Washington.

Stroll through a wonderland of stupendous moss-covered trees.

A tiny red pebble marks what may be the quietest outdoor spot in the United States.