Zoo, botanical garden and natural history museum featuring the plants and animals of the Sonoran desert.
One of the country's newest cavern complexes.
The world's largest collection of optical telescopes. Tour the museum or enjoy evening stargazing.
One of the Southwest's best-preserved Spanish missions.
Tour a former western movie set.
A turn-of-the-century copper mine.
Preserving the saguaro cactus.
A former Titan missile silo, closed at the end of the Cold War.
Site of the famous shootout at the OK Corral.
The ruins of three Spanish colonial missions built in 1691 and 1756.