The nation's largest city park, South Mountain Park located in Phoenix, AZ. is more than 16,500 acres big spanning some 11 miles long. Given to the City of Phoenix by the U.S. Government 75 years ago, the park is home to 150 animal species and 274 type of plants. Miles of trails take you to indian ruins, petroglyphs and hidden valleys. A great place to drive and visit. Three visits to the park in Feb and March 2005 show the effects of frequent winter rains in the Southwest.