These curious caverns have been home to mushrooms, gangsters, and disco.

This large midwestern cavern features impressive rock formations and an underground waterfall.

A museum within a museum, devoted to history's most questionable medical devices.

The famed architect designed this Minnesota gas station of the future with a lookout tower.

Half of a waterfall goes into the river while the other half seems to disappear.

An ADA-accessible trail and deck offering stunning views of Colorado’s Mount of the Holy Cross.

The home of a formerly enslaved man who went on to become a prospector, entrepreneur, and activist for Black rights.

This now-abandoned outcrop is an important Native American spiritual site, overtaken by European settlers and mining pollution.

A remote sandstone plateau named for a legendary cattle rustler.

A focal point of in Denver’s skyline for over a century, inspired by a Venetian basilica.

A tribute to Loveland’s most famous sweethearts, who helped spread cupid’s message to millions.

Historic, 19th-century wagon wheel ruts cut into soft volcanic ash.

One of the few surviving Panama Canal steam shovels stands outside a tiny Colorado mining museum.

This statue of an obscure comic strip hero stands as a tribute to patriotic service and a cautionary tale about embracing fads.

The final resting spot of the Colorado Transportation Department's beloved unofficial mascot.

Once a lonely sentinel on the edge of the Great Plains, this rebuilt trading fort offers a glimpse of life on the Santa Fe Trail.

This restored farmhouse is a time capsule of a 19th-century Colorado homestead.

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

Paleoamericans built these ancient walls high in the Colorado Rockies as part of an extensive hunting system.

The giant stump of the once towering cottonwood where Ute people held tribal meetings.

A coal fire has been burning underground here since 1896.

This three-mile concrete levee in Pueblo, Colorado was transformed into the world’s longest painting.

The remains of a World War II-era Japanese American internment camp dot a windswept Colorado hill.

One man's love for East Coast diner culture brought an entire eatery all the way from New Jersey to Colorado.