Unlike most arches, this geological oddity formed in a volcanic dike.

An antique narrow gauge railway line still running through the Colorado and New Mexico mountains.

The ancient dwellings of the Puebloans, located in the cliffs of majestic mesas.

The marker offers a rare chance to be in four U.S. states at once, though there's some controversy over its geographic accuracy.

A river runs through this remote valley in a very unexpected way.

Community owned and operated, this property is home to a diverse set of nudists.

Climb to the top of this spiritual tower, and you'll be rewarded with spectacular views.

When ecosystems collide in the arid Southwest.

The largest self-built castle in the U.S., six decades in the making.

The Denver airport is guarded by a 32-foot-tall sculpture of a demonic horse.

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.

Come for the speed, leave in love with the desert.

A 90-foot-tall psychedelic "tree" on the side of the highway has baffled passersby for decades.

The location along the shores of the Great Salt Lake of what was once called, "The Coney Island of the West", now sits barren due to arson and time.

The fifth-longest natural arch in the world, and the longest outside China.

Once a menacing challenge for trailblazers, this trail is now the most scenic drive in Utah.

Bizarre lunar-like landscape with thousands of large stone "hoodoos."

This raised bulls-eye visible from space was the subject of an intense geologic controversy.

Few things look more out of place than the electric blue ponds in the reddish-brown desert of Utah.

Oddly shaped rock formation, misassociated with a nearby utopian community.

One of the world’s largest collections of petroglyphs records 2,000 years of human activity.

This rugged area of red rocks and arches is often considered one of the most beautiful places on Earth.

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