The fifth-longest natural arch in the world, and the longest outside China.

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

This rugged area of red rocks and arches is often considered one of the most beautiful places on Earth.

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

If drivers cross the rumble strip on this stretch of Route 66 at just the right speed it plays "America the Beautiful."

Famously misunderstood wonder of the ancient world

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

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

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

The stone circle honors the 19 firemen who perished during the Yarnell Hill Fire.

A geological mystery on Camelback Mountain.

Take a monster truck tour around an ostrich farm in the middle of the desert.

Come for the pizza, stay for a performance on the world's largest theater pipe organ.

Founded by members of the Tohono O’odham Nation, this one-room joint's James Beard–winning fry bread is light as a cloud.

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

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

The world's largest rose bush has literally outgrown the pioneer museum it was planted behind.

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

Limestone caves with spectacular showcase chambers.

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

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

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.