Colorado's only active volcano last erupted around 4,000 years ago.

On the edge of grassland in northeastern Colorado, these rock formations are some of the few remnants of a high plain that has eroded away over millions of years.

Once named the “world’s oldest gas station” due to its unusual construction material.

A surprising collection of bronze faces beneath a bridge in Loveland.

Ute tour guides have been sharing the ancient dwellings and rock art inside this large park with visitors for more than 40 years.

The giant stump of the once towering cottonwood where Ute people held tribal meetings.

A dangerous narrow-gauge railroad once traced a route through this striking canyon.

This enigmatic building features numerous architectural styles.

This old train trestle and collapsed tunnel once allowed the railroad to negotiate the steep slopes of the Colorado Rockies.

This remote Colorado canyon is home to the second-largest collection of natural arches in the world.

One of few remaining antique carousels with stationary animals in the U.S.

This underfoot portrait is the work of a disgruntled painter inspired by a tragic poem.

Each year, teams of the world's best snow sculptors have 65 hours to create frozen masterpieces.

A prehistoric rock shelter that's literally in someone's backyard.

This nearly abandoned town was once a thriving mining community until a series of fires.

Isak Heartstone, a 15-foot wooden troll made out of recycled materials.

The burial grounds of a secret society includes fences topped with fake Tesla balls.

Two creeks flow out of either end of this canyon in opposite directions.

A home covered with elaborate mosaic and other pieces of art.

At one time this small mining village was the highest town in America but now it sits abandoned while the mine churns on.

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

The remains of the dam that unleashed a 15-foot wall of water on Denver.

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

The moving metal works of one troubled artist can still be viewed on his front lawn... for now.