This once-booming Gold Rush town is now home to a herd of feral donkeys.

Giant, natural amphitheaters made of delicate geological formations called "hoodoos."

The largest wildlife crossing in Utah allows local fauna to safely traverse the six-lane Interstate 80 at Parleys Canyon.

A tunnel with windows, so you don't miss out on the impressive views.

Come for the speed, leave in love with the desert.

This site is home to ancient petroglyphs and pictographs dating back to 6,000 B.C.

This Moab institution functions as both a rock store and a small natural history museum.

It's safe—and permitted—to walk across these twin natural sandstone arches.

This Yellowstone geyser may not shoot as high as the nearby Old Faithful, but it erupts for considerably longer.

The largest hot spring in the United States is, as the name suggests, a stunning show of natural color.

One of nature's most well-scheduled phenomenons resides in Wyoming's Yellowstone National Park.

An architect's childhood fantasy treehouse made real.

A beautiful geyser under environmental threat.

A small side chapel in Santa Fe's basilica is home to the oldest statute of the Virgin Mary in North America.

This southwest-styled home in Santa Fe claims to be the oldest house in America thanks to an ancient bit of foundation.

A preserve with 75,000 ancient drawings remains the realm of public – not just scientific – exploration.

Legends surround this jagged rock formation in the New Mexico desert.

A multi-storied adobe complex has been inhabited for more than a thousand years.

The second-largest cave chamber in the world was discovered in 1898 by a 16-year-old and a friend known as "Pothead."

An ode to "The Queen of Appalachia."

The mysterious 855-foot zigzagging stone wall has been baffling people for centuries.

This monster board rode a monster wave to break two world records.

The Flatiron Building's storied West Coast cousin is a lot more into religion.

This Oakland fairytale kingdom, fiercely devoted to childlike whimsy, was an early inspiration for Disneyland.