An acoustic anomaly with a mysterious cause.

One woman's UFO-themed campground, complete with self-built energy vortexes, UFO-themed weddings, and magic bushes.

When ecosystems collide in the arid Southwest.

Remants of foundations, streets, and streetcar tracks inhabit the cliffs where a landslide occurred in 1929.

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

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

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

This razorback ridgeline has doubled as a scenic drive since the early 1900s.

The highest bridge in America was built for an almost unnervingly small amount of money.

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

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

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

While most of the games in this arcade take quarters, that would have been a small fortune when they were made.

This super steep hike ascends 2,000 feet in less than a mile.

These faux-cliff dwellings allow visitors to climb around on a replica archaeological site.

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

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

Paranormal experiences in this hotel's room 217 led Stephen King to write "The Shining."

Air Force Academy Chapel made of 100 identical tetrahedrons works to inspire those of all religions.

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.

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

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

This tea house was a hand-built gift from Boulder's sister city in Tajikstan.

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