
Tourists visit Chengde Mountain Resort, an UNESCO World Cultural Heritage, in Chengde City, north China's Hebei Province, Aug. 3, 2017. Chengde Mountain Resort once served emperors of the Qing Dynasty (1644-1911). (Xinhua/Liu Huanyu)

Tourists visit Chengde Mountain Resort, an UNESCO World Cultural Heritage, in Chengde City, north China's Hebei Province, Aug. 3, 2017. Chengde Mountain Resort once served emperors of the Qing Dynasty (1644-1911). (Xinhua/Liu Huanyu)