Ning-yuan fu, Yunnan, China (Google Maps ⧉, OpenStreetMap ⧉)

"The best part for navigation is above this, from Ning-hia to Chaghan Kuren (in about 110° E. long.), in which Captain Prjevalski’s observations give a fall of less than 6 inches per mile."

"…the official route from Ya-chau to Ning-yuan lays down 13 stages, but it generally takes from 15 to 18 days."

"Caindu or Ning Yuan was, under the Mongols, a dependency of Yun Nan, not of Sze Ch’wan."