This gallery of prehistoric red ochre art lines the wall of a scenic segment in Utah's San Rafael Swell.

An immersive environment that is part haunted house, part choose-your-own-adventure, and part jungle gym.

One man has carved a number of natural New Mexico caves into psychedelic sandstone temples.

A phenomenal assembly of pueblos in New Mexico is the most complete example of ancient ruins north of the border.

A subterranean playground in an abandoned slate mine.

The gorgeous entrances into the city's underbelly look more like grand halls than subway stops.

Seemingly grown on some other world, these New Mexico rock formations look like a disused science fiction set.

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

This museum boasts the ninth-largest collection of insects in North America.

Acres of natural wonders left behind by a socialite-turned-gardener.

The rocks in this arid basin leave trails of movement behind them.