Sightseeing boats sail on the coast off Gulangyu island in Xiamen City, southeast China's Fujian Province, Oct. 2, 2017. Local authority took measures to limit the passenger flow on the small island during the National Day holiday, with no more than 50,000 visitors per day. The island in Xiamen entered the UNESCO world heritage list in July this year for its cultural history and historic buildings. (Xinhua/Jiang Kehong)