Thousands of Mexican Free-Tailed Bats soar around an abandoned storm drain at sunset each summer.

The largest natural travertine bridge in the world is nestled in a small canyon in central Arizona.

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

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

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.

A stealthy Apache hideaway that became the haunting site of a mass grave.

An arsenic-filled pool in the Grand Canyon takes on the appearance of a giant, overflowing pumpkin.

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

Dramatic river bend surrounds a natural red-rocked pedestal.

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

Rippling sand dunes frozen in the Arizona rock.

This natural marble cave is one of only five national monuments in Oregon.

Sasqu(w)atch out!

A vertically floating hemlock controls the waves and weather at Crater Lake.

Formerly secret, precariously perched boulders.

Despite a legend that says this highest peak in Oregon was climbed in high heels scores of people have died on its slopes.

Massive crater in central Oregon.

Only known mainland rookery of the threatened Stellar sea lion.

This lake in the Cascades lives up to its name, disappearing down a hole every spring.

Oregon's unexpected high desert, displaying layers of time in a colorful show.

The magic's in the hole!

Hollowed out cedar log tubs set in an ancient towering forest.

The deepest lake in the United States, and once the site of epic destruction that lives on in legends.