Clouds hang over the Saihanba National Forest Park in Chengde City, north China's Hebei Province, Aug. 26, 2018. (Xinhua/Liu Mancang)

Photo taken on Aug. 26, 2018 shows the scenery in Saihanba National Forest Park in Chengde City, north China's Hebei Province. (Xinhua/Liu Mancang)

Tourists enjoy the scenery in Saihanba National Forest Park in Chengde City, north China's Hebei Province, Aug. 26, 2018. (Xinhua/Liu Mancang)

Tourists enjoy the scenery in Saihanba National Forest Park in Chengde City, north China's Hebei Province, Aug. 26, 2018. (Xinhua/Liu Mancang)