A little-known hot spring haven right below the highway.

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

The superstar of Cold War nuclear bunkers has been featured in countless films but is now barely operational.

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

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

Hidden beneath a bridge, this waterfall is known for the large amounts of graffiti painted on its base.

Abandoned silver mine strewn with wrecked and twisted structures.

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

A museum of natural history, Edwin Carter's original log cabin home and workshop houses taxidermy specimens.

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

The world's largest carnivore sanctuary is home to over 450 meat-eating rescues.

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.

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

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

In the middle of a suburban Denver neighborhood is a cave that once provided solace for a prominent Ute chief and his family.

An impressive collection of over 50,000 minerals including moon rock from the Apollo 17 mission.

Where scientists keep miles of very valuable ice from Antarctica and Greenland from melting.