Aerial photo taken on April 24, 2019 shows the scenery of Yuhuagu scenic spot in Qianxi County of Tangshan City, north China's Hebei Province. (Xinhua/Yang Shiyao)

Tourists visit the Yuhuagu scenic spot in Qianxi County of Tangshan City, north China's Hebei Province, April 24, 2019. (Xinhua/Yang Shiyao)

Tourists visit the Yuhuagu scenic spot in Qianxi County of Tangshan City, north China's Hebei Province, April 24, 2019. (Xinhua/Yang Shiyao)

Aerial photo taken on April 24, 2019 shows the scenery of Yuhuagu scenic spot in Qianxi County of Tangshan City, north China's Hebei Province. (Xinhua/Yang Shiyao)

Tourists visit the Yuhuagu scenic spot in Qianxi County of Tangshan City, north China's Hebei Province, April 24, 2019. (Xinhua/Yang Shiyao)

Aerial photo taken on April 24, 2019 shows the scenery of Yuhuagu scenic spot in Qianxi County of Tangshan City, north China's Hebei Province. (Xinhua/Yang Shiyao)