Bashidang is a late Pengtoushan culture settlement in Hunan China. Site features China's earliest wall and outer ditch. Central star-shaped platform served ceremonial purposes. Residents cultivated rice water caltrop and lotus. Over 15000 rice grains found largest in Chinese Neolithic sites. Rice grains match modern domesticated size. Multiple cultivated rice types present. Only southern China Neolithic-to-Bronze site with soybeans.