A plaque marks a former safe house on the secret route, now hidden next to a McDonald's.

These pretty kitties killed and ate as many as 135 railway workers.

A hollow cement depiction of time's inexorable effect on the human body.

A century-old hotspot for jazz, frequented by everyone from Charlie Chaplin to Al Capone.

Despite being one of the most photographed vistas in the Rockies these twin peaks are rightfully known as the "Deadly Bells."

One lonely, modern pyramid has gone from corporate think tank to deserted boondoggle.

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

The haunted reputation of these abandoned Colorado train tunnels is probably not helped by the terrifying spiked fence.

A meditative space out of a fantasy story.

The hike through a narrow river flanked by the 2,000-foot-tall walls of Zion Canyon is one of the best in the world.

This granite monument at the site of an ill-conceived tourist attraction is built from the same stone as the Mormon Temple.

This museum remembers the tough Mormon trek across America through an intriguing array of artifacts.

Odd outsider art installations surround a Gold Rush-era ghost town.

The remains of this early 20th century refinery loom on a mountainside like a graffiti-covered fortress.

A ghost town that held steady longer than most, but finally gave up the ghost.

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

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

Silver in the hills led to the speedy creation of this boom town and a lack of it saw the town abandoned nearly as quickly.

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