Photo taken on Dec. 21, 2016 shows world's oldest giant panda "Pan Pan" at the Dujiangyan Base of China Conservation and Research Center for the Giant Panda in southwest China's Sichuan Province. There are eight giant pandas above 20 living at the Dujiangyan base. The Dujiangyan base, which undertakes the work of disease control and prevention for pandas, also acts as a nursing home for aged pandas. (Photo/Xinhua)
