Photo taken on Dec. 4, 2017 shows a watchtower site on the Guangwu Great Wall section built during the Ming Dynasty (1368-1644) in Shanyin County, north China's Shanxi Province. (Xinhua/Zhan Yan)

Photo taken on Dec. 5, 2017 shows the site of an arch door on the Guangwu Great Wall section built during the Ming Dynasty (1368-1644) in Shanyin County, north China's Shanxi Province. The arch door on the Great Wall was reduced to ruins after a strong gale in October last year. Now the reinforcements and repair work have been completed on the arch door site. The archway had been the remains of a former watchtower on the Guangwu Great Wall. It was called the "Moon Gate" by Great Wall aficionados due to its round shape. (Xinhua/Zhan Yan)

Photo taken on Dec. 5, 2017 shows the site of an arch door on the Guangwu Great Wall section built during the Ming Dynasty (1368-1644) in Shanyin County, north China's Shanxi Province. The arch door on the Great Wall was reduced to ruins after a strong gale in October last year. Now the reinforcements and repair work have been completed on the arch door site. The archway had been the remains of a former watchtower on the Guangwu Great Wall. It was called the "Moon Gate" by Great Wall aficionados due to its round shape. (Xinhua/Zhan Yan)

Photo taken on Dec. 5, 2017 shows the Guangwu Great Wall section built during the Ming Dynasty (1368-1644) in Shanyin County, north China's Shanxi Province. (Xinhua/Zhan Yan)

Photo taken on Dec. 5, 2017 shows the Guangwu Great Wall section built during the Ming Dynasty (1368-1644) in Shanyin County, north China's Shanxi Province. (Xinhua/Zhan Yan)