The world's longest known cave system.

The mysterious white squirrels of this Illinois city are treated like sacred cows.

The Old Courthouse takes visitors on a captivating trip through St. Louis' timeline.

Two hundred tons of pioneer artifacts were painstakingly recovered from a shipwreck at the bottom of the Missouri River.

The wreckage of a World War II bomber is hidden high in the Colorado wilderness.

A natural formation that resembles a camel resting in the New Mexico desert.

Here, at the "world's longest art gallery," you'll find forty miles of ancient petroglyphs and pictographs.

The unusual patterns in this rock formation result from two distinct modes of weathering.

A tunnel with windows, so you don't miss out on the impressive views.

Settled by the Church of Jesus Christ of Latter-day Saints in 1859, this abandoned frontier town has appeared in several films.

A motel dedicated to Southwestern nostalgia.

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

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

Crafted in 1911, this steam locomotive spent its entire working life in Flagstaff.

A museum devoted entirely to the rattlesnakes and snake-related art.

These Pre-Columbian petroglyphs contain representations of birds, deer, hunters, and even some early Native flute players.

Behind the Cowboy Hall of Fame is a burial ground for good horses and a famed rodeo bull.

Sitting in the arguable birthplace of the Wild West, this museum holds the largest collection of bronco busting bric-a-brac in the world.

Collection of skeletal systems from the "world's leading supplier of osteological specimens."

This futuristically sylvan church is a glass-enclosed marvel of modern architecture.

Town not known for anything except its strange name.

This haunted hotel built on natural springs once served as a hospital for a quack doctor promising a cure for cancer.

An extravagant western hotel where every floor is the "ground floor."

Bananas are often left for the first monkey America ever recovered alive after being launched into space.