Ancient pueblos built into the base of a natural canyon wall.

Some of the tallest ancient American ruins continue to inspire awe and curiosity.

This historic national park is covered in the stunning ruins of red rock pueblos.

Ancestral Puebloan ruins, natural arches, and box canyons abound in this seldom-visited corner of Monument Valley Navajo Tribal Park.

Ninety feet off the valley floor is an ancient dwelling put under protection of the U.S. government by Teddy Roosevelt.

This secluded aqua waterfall in the Grand Canyon is the perfect swimming hole, and the Havasupai tribe's fiercely protected natural wonder.

A sharp bend in a dramatic river canyon cut through red rocks.

Most-visited and most-photographed slot canyon in the American Southwest.

One of the ghostly stops along Route 66.

These millipedes glow not out of attraction, but as a not-too-subtle warning.

Quite simply the largest tree in the world (by volume).

The remains of a historic ranch house that witnessed the Civil War battle dubbed the “Gettysburg of the West.”

Despite time, colonization, and the brutal New Mexican heat, these Pueblo ruins still stand.

The marker offers a rare chance to be in four U.S. states at once, though there's some controversy over its geographic accuracy.

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

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

The largest dinosaur trackway in North America is tucked away among this canyon's ghosts and archaeological gems.

This otherwise unremarkable ski town building marks the site of Butch Cassidy's first robbery.

The scene of one of the darkest moments in American labor history has been left essentially untouched since the tragedy.

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

One of the largest Buddhist stupas in North America is built of concrete designed to last 1,000 years.

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

Paranormal experiences in this hotel's room 217 led Stephen King to write "The Shining."

When ecosystems collide in the arid Southwest.