The Hengduan Mountains () are a group of mountain ranges in southwest China that connect the southeast portions of the Tibetan Plateau with the Yunnan-Guizhou Plateau. The Hengduan Mountains are primarily large north-south mountain ranges that effectively separate lowlands in northern Myanmar from the lowlands of the Sichuan Basin. These ranges are characterized by significant vertical relief originating from the Indian subcontinent's collision with the Eurasian Plate, and further carved out by the major rivers draining the eastern Tibetan Plateau. These rivers, the Yangtze, Mekong, and Salween, are recognized today as the Three Parallel Rivers UNESCO World Heritage Site.