The world's largest military aircraft cemetery.

The contents of this safe survived a 37-kiloton nuclear bomb.

The largest man-made crater in the U.S. marks the spot where we once tested mining with nukes.

Dyed by iron oxide over centuries, these sandstone rocks rise thousands of feet into the sky.

A monument to the one-armed geologist who led the first documented expeditions through the Grand Canyon.

The drama of nature in full effect in this Nevada State Park.

Nearly 300,000 acres of wildlife, natural splendor, and a hidden ghost town have been designated a national monument.

The lost ruins of the forgotten ferry lie hidden beneath the silt.

Once America’s most beautiful army base, this abandoned military fort on the coast of Monterey Bay has been left to the elements.

Odd outsider art installations surround a Gold Rush-era ghost town.

The eerie ruins of an isolated abandoned town nicknamed "the Widowmaker" for its deadly gold mine.

The overgrown ruins of a once thriving World War I-era copper mine.

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

An eatery for UFO seekers on the Extraterrestrial Highway.

This Old West prison built into the side of a cliff was said to be inescapable.

This secluded aqua waterfall in the Grand Canyon is the perfect swimming hole, and the Havasupai tribe's fiercely protected natural wonder.

A pair of giant roadside arrows are all that remains of a former Route 66 trading post.

This 4,000-foot-diameter hole is touted as "the most well known, best preserved meteorite crater on Earth."

This 40-room dwelling tucked within a cliff was built by the basin's prehistoric residents.

The eroded core of an ancient volcano is now accessible by a short hike.

An incredible airplane graveyard sits outside this small museum dedicated to preserving aviation history.

This golf ball–shaped former desert real estate office now houses a UFO museum.

No one's quite sure why there's a metal megaphone bolted on two rocks in the middle of the Mojave Desert.

A pair of large white marble lions guard this stretch of the Mojave Desert, and it is utterly mysterious how they got there.