Photo taken on June 18, 2020 shows a view of the western royal tombs of the Qing Dynasty (1644-1911) in Yixian County, north China's Hebei Province. The western royal tombs of the Qing Dynasty is the burial place of four emperors of the Qing Dynasty, namely Yong Zheng, Jia Qing, Dao Guang and Guang Xu. It was included into the World Heritage List in 2000. (Xinhua/Zhu Xudong)

Photo taken on June 18, 2020 shows a statue on the stone gate of the underground palace of the western royal tombs of the Qing Dynasty (1644-1911) in Yixian County, north China's Hebei Province. The western royal tombs of the Qing Dynasty is the burial place of four emperors of the Qing Dynasty, namely Yong Zheng, Jia Qing, Dao Guang and Guang Xu. It was included into the World Heritage List in 2000. (Xinhua/Zhu Xudong)

Photo taken on June 18, 2020 shows a stone altar in the western royal tombs of the Qing Dynasty (1644-1911) in Yixian County, north China's Hebei Province. The western royal tombs of the Qing Dynasty is the burial place of four emperors of the Qing Dynasty, namely Yong Zheng, Jia Qing, Dao Guang and Guang Xu. It was included into the World Heritage List in 2000. (Xinhua/Zhu Xudong)

Photo taken on June 18, 2020 shows a view of the western royal tombs of the Qing Dynasty (1644-1911) in Yixian County, north China's Hebei Province. The western royal tombs of the Qing Dynasty is the burial place of four emperors of the Qing Dynasty, namely Yong Zheng, Jia Qing, Dao Guang and Guang Xu. It was included into the World Heritage List in 2000. (Xinhua/Zhu Xudong)

Aerial photo taken on June 18, 2020 shows a view of the western royal tombs of the Qing Dynasty (1644-1911) in Yixian County, north China's Hebei Province. The western royal tombs of the Qing Dynasty is the burial place of four emperors of the Qing Dynasty, namely Yong Zheng, Jia Qing, Dao Guang and Guang Xu. It was included into the World Heritage List in 2000. (Xinhua/Zhu Xudong)

Aerial photo taken on June 18, 2020 shows a view of the western royal tombs of the Qing Dynasty (1644-1911) in Yixian County, north China's Hebei Province. The western royal tombs of the Qing Dynasty is the burial place of four emperors of the Qing Dynasty, namely Yong Zheng, Jia Qing, Dao Guang and Guang Xu. It was included into the World Heritage List in 2000. (Xinhua/Zhu Xudong)