Samsu

Samsu lies in the mountainous upper Yalu basin, where the Changjin and Hŏch'ŏn rivers join the great frontier river. Its name, meaning “three waters,” is thought to recall these waterways. Originally a fort of Gapsan, Samsu gained its own military commander in 1441. A stone town wall was built in the mid-fifteenth century, when the Joseon court strengthened defences along the northern frontier. The administrative seat was moved to the walled town in 1464.