Aerial photo taken on Aug. 9, 2020 shows the scenery in Saihanba National Forest Park in Chengde, north China's Hebei Province. (Photo by Liu Mancang/Xinhua)

Aerial photo taken on Aug. 9, 2020 shows the scenery in Saihanba National Forest Park in Chengde, north China's Hebei Province. (Photo by Liu Mancang/Xinhua)

Aerial photo taken on Aug. 9, 2020 shows the scenery in Saihanba National Forest Park in Chengde, north China's Hebei Province. (Photo by Liu Mancang/Xinhua)

Aerial photo taken on Aug. 9, 2020 shows the scenery in Saihanba National Forest Park in Chengde, north China's Hebei Province. (Photo by Liu Mancang/Xinhua)

Tourists have fun in Saihanba National Forest Park in Chengde, north China's Hebei Province, Aug. 9, 2020. (Photo by Liu Mancang/Xinhua)