Southern Arizona is dominated by two equal presences: the vast Sonoran Desert, and Tucson, the modern metropolis that rises in the middle of it.
The city of Tucson, and the surrounding communities, are a blend of Spanish, Mexican, and Anglo influences, with a very large Indian presence. This is the area most strongly associated with the "Old West." But for all that, Tucson is a modern metropolis, with world-class spas and golf courses, a major university (the University of Arizona), and a growing population of sunbirds who have come to enjoy the warm, dry weather.
Tucson, because it lies at a higher elevation, enjoys both cooler temperatures and more rainfall than Phoenix. Still, the summers can be very hot; but they're balanced by winter temperatures that rarely dip below freezing. For six months of the year, Tucson enjoys weather that other regions of the country associate with fall: cool, dry, and sunny. Tucson, in fact, averages even more sunny days than Phoenix: 340 days a year.
Outside Tucson lies the Sonoran Desert, home of the unique saguaro cactus. Although nearly all Americans are familiar with the saguaro—indeed, it's probably the first image that comes to mind with the word "cactus"—few realize that this is actually the only part of the West where it grows.