Nanling (nänˈlĪngˈ) [key], mountain range of Guangdong and Hunan prov. and Guangxi Zhuang Autonomous Region, S China; rises to c.6,900 ft (2,100 m). The Nanling form the geographical boundary between central and S China. They separate the Chang and Xi drainage basins, protect S China from cold northern air masses, and divide the Cantonese civilization and linguistic area from that of central China. The mountains lie in parallel ridges that hinder north-south travel.