The Quây Sơn River (Vietnamese: Sông Quây Sơn, Sông Quế Sơn; chữ Nôm: 滝山, 滝桂山)[1] or as the Guichun River as it is known in China, (Chinese: 归春河, Pinyin:) is a river that passes through Cao Bằng Province, Vietnam and Guangxi province, China.[2] The river originates in China in Jingxi County in the Chongshan Mountain Range (Chinese:崇山峻岭, Pinyin: Chóngshān jùnlǐng).[3]
For part of its length it runs along the Chinese–Vietnamese border, including the scenic Bản Giốc–Detian Falls.