Aerial views of Wanlyuyuan park in Haikou City, S China's Hainan

Citizens do morning exercise at Walyuyuan park in Haikou City, south China's Hainan Province, Oct. 23, 2018. Areas along the Meishe river used to be garbage dumps. After two years' wetland restoration, the once filthy areas transformed into good places for leisure activities with powerful function of sewage purification. (Xinhua/Yang Guanyu)