Native Americans built this circle of stones, which was used to predict astronomical events.

One of nature's most well-scheduled phenomenons resides in Wyoming's Yellowstone National Park.

The largest hot spring in the United States is, as the name suggests, a stunning show of natural color.

A beautiful geyser under environmental threat.

The first declared National Monument in the United States.

An experimental, automotive replica of Stonehenge.

This geothermal hot spring hides beneath a slowly growing mineral dome.

A miraculous natural phenomenon known as "the spring that breathes."

A waterfall 600 ft. inside a mountain, once the bane of gold miners, is now a spectacle of nature.

Other-worldly rock formations and ancient fossils abound in this unique stretch of Nebraska badlands.

This erect, phallic geological spire wasn't always named so domestically.

London's creepiest cemetery was once the site of dueling magicians and mobs of stake-carrying vampire hunters.

Wondrous sandstone hoodoos where Native Americans collected clay for pottery, 9,000 years ago.

The highest paved road in North America winds its way up Mount Blue Sky in Colorado to an altitude of 14,130 feet above sea level.

Strange red rock formations that have been attributed to a higher power for hundreds of years.

Crystal clear lake with a shoreline of travertine located in a Colorado canyon.

Thanks to a quirk of elevation this gift shop produces magic doughnuts that are found nowhere else on Earth.

This naturally-sourced hot spring is now home to a clothing-optional resort.

Giant, natural amphitheaters made of delicate geological formations called "hoodoos."

Rippling sand dunes frozen in the Arizona rock.

See massive fossils that are over 200 million years old in northeastern Arizona.

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

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

A ghost town revived by hippies and wanderers throws its own special brand of holiday parade.