Warm Springs is the most famous of Georgia's seven known warm springs. It has the largest flow of up to 914 gal/min (58 L/s) with an average temperature of 88°F (31°C). The springs issue from at least 12 separate locations along a 500-ft (150-m) long belt in the edge of a quartzite hillside. Most of the discharge (550 gpm - 35 L/s) flows from the middle 25 ft (8 m) of this belt. The springs are located in the Central Georgia Upland on the Greenville Plateau of the Piedmont (elevation 1,000 ft - 300 m) approximately 75 miles (120 km) southwest of Atlanta. Based on a temperature gradient of 1.2°F/100 feet (22°C/km), it is estimated that the spring water is heated by circulation to a depth of 3,800 feet (1,160 m) in quartzite, gneiss and schist rocks of Precambrian age