A clear blue swimming hole with hidden caves, still unexplored.

The final resting place of the businessman-turned-astronomer who helped discover Pluto stands near his observatory.

A mistaken marker makes an erroneous claim along the historic Old Divide Road.

The remote resting place of a notorious Wild West outlaw whose death is shrouded in mystery.

The unusual burial monument of Arizona's first governor.

A Wild West jailhouse that slid down the mountainside.

Collection of vintage trailers double as hotel rooms.

On the outskirts of a reborn ghost town, a decaying post office remembers the bad old days.

Once the "Eighth Wonder of the World," this iron railroad bridge was decimated by a tornado.

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

The shop's owner has spent decades in the desert wearing nothing but a strategically placed sock.

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

A nature and cultural preserve named for its multitude of petroglyphs carved by the Northern Sinagua people.

The highest point in Arizona is an oddly snow-topped peak within the otherwise arid state.

Limestone caves with spectacular showcase chambers.

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

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

Rippling sand dunes frozen in the Arizona rock.

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

Dramatic river bend surrounds a natural red-rocked pedestal.

Taxidermy and miniatures come together to create this unique museum.

The fifth-longest suspension bridge the world, connecting one Michigan peninsula to another.

Island where motor vehicles are banned -- home to the only carless highway in the United States.

This freshwater spring fills with 10,000 gallons of water per minute.