Ānsāi

Ansai lies north of Yan'an in the deeply cut hills of the Loess Plateau. Its name, meaning a secure frontier, recalls a fort established by the Song in 1072 at the old seat of Jinming County. The district faced Western Xia and saw repeated fighting; in 1216 Xia forces attacked the fort but were defeated by Jin troops. Under Mongol rule the fort became a county, later incorporating neighbouring Fuzheng. The Ming and Qing retained Ansai under Yan'an Prefecture.