Ban Gioc – Detian Falls are two waterfalls on the Quây Sơn River, in Chinese Guichun River, straddling the Sino-Vietnamese border, located in the Karst hills of Daxin. County, Guangxi from Chinese side, and in Trùng Khánh District, Cao Bằng province on the Vietnamese side, 272 kilometer north of Hanoi.A road running along the top of the falls leads to a stone marker that demarcates the border between China and Vietnam in French and Chinese. Modern disputes arose as there are discrepancies as to the correlating legal documents on border demarcation and the placement of markers between the French and Qing administrations in the 19th century.
