Aerial photo taken on Aug. 3, 2019 shows relics of the Liao Dynasty (916-1125 A.D.) imperial mausoleum and its defending city in Bairin Left Banner of Chifeng, north China's Inner Mongolia Autonomous Region. Bairin Left Banner is the birthplace of the culture of the Khitan-led Liao Dynasty. A large number of 1,100-year-old Liao cultural relics are under preservation by local authorities. (Xinhua/Peng Yuan)