Located 15 miles south of downtown Tucson. I-19 to exit 80 at Pima Mine Road. The center offers an inside look at an operating open-pit copper mine. Displays and exhibits in the Discovery Center explain the history and process of mining. Discovery Theater shows presentations related to mining and minerals. Admission to the Center is free but there is a charge for the one hour bus tour which includes views of the mining operations and a visit inside one of the copper mills. Admission fee for tour. Senior (62) discounts.