Photo taken on Aug. 13, 2019 shows a section of the Great Wall at Panjiakou reservoir in Kuancheng Manchu Autonomous County, north China's Hebei Province. A section of the Great Wall appeared on the water surface recently due to water level dropping. The section, built in the Ming Dynasty, had been submerged after Panjiakou reservoir was completed. (Xinhua/Zhu Xudong)

Photo taken on Aug. 13, 2019 shows a section of the Great Wall at Panjiakou reservoir in Kuancheng Manchu Autonomous County, north China's Hebei Province. A section of the Great Wall appeared on the water surface recently due to water level dropping. The section, built in the Ming Dynasty, had been submerged after Panjiakou reservoir was completed. (Xinhua/Zhu Xudong)

Photo taken on Aug. 13, 2019 shows a section of the Great Wall at Panjiakou reservoir in Kuancheng Manchu Autonomous County, north China's Hebei Province. A section of the Great Wall appeared on the water surface recently due to water level dropping. The section, built in the Ming Dynasty, had been submerged after Panjiakou reservoir was completed. (Xinhua/Zhu Xudong)

Photo taken on Aug. 13, 2019 shows a section of the Great Wall at Panjiakou reservoir in Kuancheng Manchu Autonomous County, north China's Hebei Province. A section of the Great Wall appeared on the water surface recently due to water level dropping. The section, built in the Ming Dynasty, had been submerged after Panjiakou reservoir was completed. (Xinhua/Zhu Xudong)

Photo taken on Aug. 13, 2019 shows a section of the Great Wall at Panjiakou reservoir in Kuancheng Manchu Autonomous County, north China's Hebei Province. A section of the Great Wall appeared on the water surface recently due to water level dropping. The section, built in the Ming Dynasty, had been submerged after Panjiakou reservoir was completed. (Xinhua/Gong Zhihong)

Photo taken on Aug. 13, 2019 shows a section of the Great Wall at Panjiakou reservoir in Kuancheng Manchu Autonomous County, north China's Hebei Province. A section of the Great Wall appeared on the water surface recently due to water level dropping. The section, built in the Ming Dynasty, had been submerged after Panjiakou reservoir was completed. (Xinhua/Zhu Xudong)

Photo taken on Aug. 13, 2019 shows a section of the Great Wall at Panjiakou reservoir in Kuancheng Manchu Autonomous County, north China's Hebei Province. A section of the Great Wall appeared on the water surface recently due to water level dropping. The section, built in the Ming Dynasty, had been submerged after Panjiakou reservoir was completed. (Xinhua/Gong Zhihong)

Photo taken on Aug. 13, 2019 shows a section of the Great Wall at Panjiakou reservoir in Kuancheng Manchu Autonomous County, north China's Hebei Province. A section of the Great Wall appeared on the water surface recently due to water level dropping. The section, built in the Ming Dynasty, had been submerged after Panjiakou reservoir was completed. (Xinhua/Gong Zhihong)