This 19th-century ranch is being transformed into a residential library with thousands of books about the natural world.

Paleoamericans built these ancient walls high in the Colorado Rockies as part of an extensive hunting system.

Hidden high on a remote mountain peak is a humbling and mysterious Vietnam War memorial.

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

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

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

It would be easy to walk past this unusual piece of art and have no idea it pays tribute to the odd life of a real chicken.

Colorado's only true geyser is hidden within the San Juan National Forest.

A research lab and hands-on museum where visitors can experiment with retro technology.

The site where a nuclear bomb was lowered over 8,000 feet underground and detonated as an experiment in natural gas extraction.

A lively annual event in which thousands of people race to push coffins heavy with bodies up a hill.

A stark reminder of the huge nuclear weapons plant that once stood on the site and its effect on the surrounding area.

A fake mine that was made using real mining techniques which is also used as a community center.

This hot dog-shaped diner has moved all around Colorado, never been to New York.

A futuristic hovertrain is parked unceremoniously alongside a nondescript road.

Metal water storage tank turned ethereal concert hall.

Small teepee-like houses built for TB patients have become sheds, studios, and bus stops around Colorado Springs.

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

Once an unstoppable source of gold and silver, this town came to a grinding stop when the groundwater proved deadly.

The largest dinosaur trackway in North America is tucked away among this canyon's ghosts and archaeological gems.

A collection of fading fantasy tchotchkes lines this dirt road in the Colorado wilderness.

At the tallest peak in Colorado, an electrifying mix of thin air, lightning, and rivalry.

The scene of one of the darkest moments in American labor history has been left essentially untouched since the tragedy.

Gleaming self-built castle towers made from beer cans and inspired by "Vitamin Mary Jane."