Kartchner Caverns State Park is an Arizona state park, located nine miles (14 km) south of the town of Benson. The park encompasses most of a down-dropped block of Palaeozoic rocks on the east flank of the Whetstone Mountains in the Coronado National Forest. It is carved out of limestone and filled with spectacular speleothems which have been growing for 50,000 years and longer, and are still growing due to careful development and maintenance.