At certain times in the fall and winter, the sunlight makes this natural sandstone arch glow.

Archaeologists believe this panel of petroglyphs depicting descending sheep and other figures in Glen Canyon are 3,000 to 6,000 years old.

This mesmerizing and surreal landscape features intricate patterns of white and red sandstone.

This ancient trail has claimed the lives of over 2,000 people.

Some 10,000 works of ancient rock art cover these volcanic basalt outcrops near the Gila River.

Red sandstone structures dominate this landscape, which has been inhabited for some 5,000 years.

This oasis-like spring in the Sonoran Desert is home to unique, endangered species.

The biggest solar telescope in the world helps reveal the secrets of our sun.

More than 300 years ago, a revolt at this Hopi pueblo shaped the future of the American Southwest.

An Arizona museum with a collection of pharmaceutical oddities, including a jar of a gangster's chewed gum.

A Tucson museum and performance space full of found-object movable sculptures.

This 40-room dwelling tucked within a cliff was built by the basin's prehistoric residents.

This Arizona observatory is famous for investigations into Martian life, and as the place humans first spotted Pluto.

Limestone caves with spectacular showcase chambers.

America's only nuclear missile silo open to the public.

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.

Eons ago, a rushing lava river formed this pristine passage through solid rock.

See massive fossils that are over 200 million years old in northeastern Arizona.

This 4,000-foot-diameter hole is touted as "the most well known, best preserved meteorite crater on Earth."

The installation’s official name, “You Who Are Getting Obliterated in the Dancing Swarm of Fireflies,” says it all.

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

Rippling sand dunes frozen in the Arizona rock.