Photo taken on Aug. 8, 2018 shows sea of clouds after a rainfall at Huangyaguan section of the Great Wall in Tianjin, north China. (Xinhua/Wang Guangshan)

Photo taken on Aug. 8, 2018 shows sea of clouds after a rainfall at Huangyaguan section of the Great Wall in Tianjin, north China. (Xinhua/Wang Guangshan)