To learn more about Tucson’s copper-mining past and present, head 15 miles south of Tucson to tour this huge open-pit copper mine, still an active working mine. One-hour mine tours are offered four times a day (call for summer days and hours). The center also has exhibits and a video about the copper mining process, and large items of vintage mining equipment are set around the desert landscape outside. You might want to combine this with a visit to the nearby Titan Missile Museum (