The world's largest key collection features keys to the White House, Frankenstein's castle, and Hitler's bunker.

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

The largest source of fossilized insects anywhere.

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

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

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.

One of the greatest heroes of the Titanic tragedy came from humble beginnings to this beautiful home.

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.

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.

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

When ecosystems collide in the arid Southwest.

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

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

This "zoo" is a cross between a junkyard and a sculpture garden, featuring animals you won't see anywhere else.

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

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

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.

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

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