Photo taken on June 7, 2017 shows tourists visiting the Lingqu Canal in Xing'an County, south China's Guangxi Zhuang Autonomous Region. China's four ancient irrigation sites, which are Dujiangyan irrigation system, the Lingqu Canal, the Jiangxiyan irrigation system and the Changqu Canal, have been added to the World Heritage Irrigation Structures list by the International Commission on Irrigation and Drainage (ICID). (Xinhua/Lu Boan)