Yan Jing of Mang Kang county lies in the area of Chang Du of the east of Tibet,which is in the famous mining district of the three rivers.

• 盐井属于藏东昌都地区芒康县,地处于著名的三江成矿区;藏东地质构造复杂,成矿条件优越,具备形成铜、金、铅、锌、银矿的地质背景,是中国重要的多金属成矿带。