This impressive tunnel was dug entirely by hand over the course of 36 years.

The largest self-built castle in the U.S., six decades in the making.

A motel dedicated to Southwestern nostalgia.

Twenty-seven massive radio antennas on the high plains of New Mexico search for life on other planets.

A multi-storied adobe complex has been inhabited for more than a thousand years.

Explore the largest pure gypsum deposit in the world, and go dune sledding while you're at it.

In the remote high desert of New Mexico, a strange array of poles beckon fury from above.

Wee (and not so wee) footprints that insects and reptiles of the Paleozoic Era left behind.

The second-largest cave chamber in the world was discovered in 1898 by a 16-year-old and a friend known as "Pothead."

Gleaming self-built castle towers made from beer cans and inspired by "Vitamin Mary Jane."

Twice a year, visitors can tour the desolate site that birthed the Atomic Age.

A unique geological area spiked with wind-carved rocks that resemble teepees.

Seller of surplus nuclear research materials.

A museum dedicated to the alleged Roswell Incident.

A sprawling collection of over 106,000 toys from around the world.

"I did this all while you were watching TV."

Beneath the mossy overgrowth covering this once-sprawling campus lies decades of history and the secrets that come with it.

Large tower used for simulating radiation of Hiroshima bomb and the tallest object ever relocated.

Secret US military film studio in the Hollywood Hills.

In the middle of an extremely unforgiving and desolate high desert is the most secret military facility in the world.

Cambria's most unique B&B features creative surroundings and fantastic food.

Decommissioned experimental solar facilities that pioneered solar energy technology.

360-degree virtual reality chamber physically immerses scientists into their data.

A ring of creosote bushes that are estimated to be 11,700 years old.