The Asarco Mineral Discovery Center is an operating open-pit copper mine located just southwest of Tucson, Arizona. Obviously copper in is very important mineral used in many products including the computer you are using to view this website. However, unlike gold which costs hundreds of dollars an ounce, copper only costs a couple dollars per pound. For this reason, copper mining can only be done economically in huge open pit mining operations such as this one. The Asarco Mineral Discovery Center offers tours of the mine including viewing the huge pit, a visit to the processing plant, and has a museum that features antique mining equipment. The huge truck you see here is an old model that is no longer used as it is too small. The tire that Julia and I are standing next to is from a current truck. Each tire costs $20,000 and they can't buy them fast enough.