Aerial photo taken on Sept. 27, 2020 shows the autumn scenery in Saihanba National Forest Park in Chengde, north China's Hebei Province. (Photo by Liu Mancang/Xinhua)

Photo taken on Sept. 27, 2020 shows the autumn scenery in Saihanba National Forest Park in Chengde, north China's Hebei Province. (Photo by Liu Mancang/Xinhua)

Tourists visit Saihanba National Forest Park in Chengde, north China's Hebei Province, Sept. 27, 2020. (Photo by Liu Mancang/Xinhua)

Aerial photo taken on Sept. 27, 2020 shows the autumn scenery in Saihanba National Forest Park in Chengde, north China's Hebei Province. (Photo by Liu Mancang/Xinhua)

Tourists visit Saihanba National Forest Park in Chengde, north China's Hebei Province, Sept. 27, 2020. (Photo by Liu Mancang/Xinhua)

Aerial photo taken on Sept. 27, 2020 shows the autumn scenery in Saihanba National Forest Park in Chengde, north China's Hebei Province. (Photo by Liu Mancang/Xinhua)

Aerial photo taken on Sept. 27, 2020 shows the autumn scenery in Saihanba National Forest Park in Chengde, north China's Hebei Province. (Photo by Liu Mancang/Xinhua)

Tourists visit Saihanba National Forest Park in Chengde, north China's Hebei Province, Sept. 27, 2020. (Photo by Liu Mancang/Xinhua)

Aerial photo taken on Sept. 27, 2020 shows the autumn scenery in Saihanba National Forest Park in Chengde, north China's Hebei Province. (Photo by Liu Mancang/Xinhua)