One of Frank Lloyd Wright's final works was this UFO church.

The famed architect designed this Minnesota gas station of the future with a lookout tower.

Hidden away in the city of Madison, Wisconsin is a nearly forgotten home that Frank Lloyd Wright built for a childhood friend.

Built by the patriotic residents of Boonsboro in a single day.

There's a 12-foot-tall replica of the Washington Monument hidden under a manhole nearby.

Natural catch-basin rocks covered in thousands of drawings spanning many millennia.

A spring-fed pool so deep it's used for scuba diving as well as swimming.

Steep canyon walls hide a forested oasis in the West Texas desert.

This is one really big nut.

Home of the International Space Hall of Fame.

This fast-food outlet is the only space and UFO-themed McDonalds in the world.

This innocuous New Mexico storefront was once the secret jump-off spot for Manhattan Project scientists.

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

An immersive environment that is part haunted house, part choose-your-own-adventure, and part jungle gym.

A burnt-out motel with priceless Native American artwork in the basement, redeveloped into apartments.

Albuquerque found the perfect use for tumbleweeds at Christmastime.

This pseudo-steampunk weapons facility is the world's largest wood and glue structure, and packs quite a wallop.

The U.S. Air Force has an anti-satellite laser weapon.

The smallest country in the world.

Beneath a Virginia City bar is the entrance to an abandoned gold mine.

An eccentric millionaire's personal curio collection includes at least one shrunken head.

These once-beautiful historic graveyards are set against the barren Virginia City hills.

Curiously, this large sporting goods store features 14 wax representations of American presidents.

This Nevada lake holds its titular natural pyramid and, if the legends are true, a number of dangerous spirits.