Bayingolin Mongol Autonomous Prefecture, often abbreviated to Bayingol (literally "rich river"), is an autonomous prefecture of the People's Republic of China, bordering Gansu to the east, Qinghai to the southeast, and the Tibet Autonomous Region to the south. It is the largest prefecture-level division nationally, with an area of , even larger than its neighbouring province of Gansu. The prefectural capital is Korla.