Huge stone depressions which may have acted as an Incan agricultural experiment.

Preserved Inca city and site of the last Inca stronghold against the Spanish conquistadors.

A Christian monastery stands on what was once a holy Incan temple.

Situated on a sacred Inca site, this 16th-century cathedral took nearly 100 years to build.

This geometric feat is a testament to the Incas' mesmerizing architectural abilities.

The stones of this Incan wall complex fit together so well you couldn't fit a piece of paper between some of them.

This largest dinosaur tracksite in Wyoming is one of the only in the world from the Middle Jurassic Period.

The highest point in Montana is as rugged and singular as the state itself.

One man's ambition created this psychedelic log home.

At the time of its completion, it was the tallest dam in the world.

Cabins once lived in by Butch Cassidy and the Sundance Kid are featured at this Old West living history museum.

An unusual geological feature towers over the remains of a dark episode in United States history.

Derelict buildings are all that remain of a complex at the site of one of the worst mining disasters in Montana history.

Operational for less than a year, this mill produced more than 11,000 tons of chrome concentrate in its short lifespan.

A creek tumbles over a series of step-like rocks to create this scenic water feature.

Supposedly Satanic numbers adorn this preserved submarine sail.

Home to the deepest rift anywhere on Earth.

This Wyoming town is fascinated by a particular mythical creature.

Devilish landscape, once cinema home to giant alien bugs, now derelict roadside attraction.

This 35-foot troll in Jackson Hole, Wyoming, was made by the world’s leading recycling artist as part of a global fairytale.

An experimental, automotive replica of Stonehenge.

Lured here by the promise of tens of thousands in gold, Jesse James started a quintessentially American trend of robbing trains in-motion.

Among the cornfields stands a giant spider crafted from an old Volkswagen.

Knoxville’s architectural icon was the symbol of the 1982 World’s Fair, even catching the googly eye of Bart Simpson.