Photo taken on Jan. 18, 2018 shows a copper mirror found in the cliff cave burial site in Zhengxing Town of Chengdu, capital of southwest China's Sichuan Province. More than 200 cave burial sites dating back to the Han Dynasty and Wei-Jin period (206 B.C.-420 A.D.) were found on high cliffs facing the Jinjiang River, which runs through the city. (Xinhua/Liu Kun)