Tucson has been continuously settled for over 12,000 years. It celebrates a diversity of cultures, architecture, and peoples. Yet, it is one of the "Mega-Trend" cities of the 21st Century: the Optics Valley, premier health services center for the Southwest, the astronomy center of the world, home of a premier research institution - University of Arizona, and a tourism destination. Tucson boasts the best of both worlds...the progress and innovation of a Rodeo Dancersmetropolitan community and the friendly, caring atmosphere of a small town. Tucson is situated in the Sonoran Desert and is surrounded by five mountain ranges. A trip from the 2,389-foot valley floor to the 9,157-foot Mt. Lemmon summit (home to the southernmost ski area in the continental United States) traverses seven of the world's nine life zones. It's like driving from Mexico to Canada. Blessed with the natural beauty of the Sonoran Desert and an unsurpassed climate of 360 sunny days a year, Tucsonans embrace a rare lifestyle and are committed to preserving that quality of life.