This once-popular otherworldly landscape was formed by one of the largest volcanic eruptions in history.

These decaying bridges 1,000 feet high are a reminder of the skill it took to cross the Colorado Rockies by rail.

Community owned and operated, this property is home to a diverse set of nudists.

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

The largest source of fossilized insects anywhere.

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

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

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

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

Abandoned silver mine strewn with wrecked and twisted structures.

An architect in Aspen used psychedelics as his muse while building this mushroom masterpiece.

This Colorado hiking trail provides a small gold mine of abandoned gold mines.

This spectacular track has run continuously since 1882.

At this Denver landmark, the meals are compulsory, the sopapillas are complimentary, and the insanity is everywhere.

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

This naturally-sourced hot spring is now home to a clothing-optional resort.

A breathtaking array of ancient Pueblo structures and artifacts counterintuitively preserved by neglect.

This modern antique shop is a museum for 1980's Saturday morning cartoon culture.

A technicolor place of worship for Elevationists.

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

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