Population: 1.

Metal water storage tank turned ethereal concert hall.

This prison-turned-museum is a remnant of the Old West's grizzly, violent past.

Long before guestbooks and hotels, frontier travelers signed their names on this rock face.

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

One of few remaining antique carousels with stationary animals in the U.S.

This erect, phallic geological spire wasn't always named so domestically.

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

When zealous marijuana enthusiasts kept stealing the "Mile 420" highway marker, the State of Colorado got creative.

Storage units with a wartime past.

A century-old cabin off of Highway 30 touts an unusual construction material: dinosaur bones.

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

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

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

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

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.

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

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

This 19th century jail was mainly used to incarcerate the drunk and disorderly.

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

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

Hidden beyond a kitschy giant beetle is this remarkably sprawling collection of preserved insects.

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

An enthusiastically interactive mining museum that won't let black lung ruin the fun.