Unlike most arches, this geological oddity formed in a volcanic dike.

There are eight natural springs around town, each with a slightly different taste.

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

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

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

These faux-cliff dwellings allow visitors to climb around on a replica archaeological site.

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

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

This spectacular track has run continuously since 1882.

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.