Sīēn

Si'en occupies the hill country around the Huan River, north of Qingyuan. Established as a county in the Tang, it belonged to Qingyuan under the Yuan and Ming. Its seat moved several times in the fifteenth century, reaching Oujia Mountain in 1472. In 1506 the county was placed under Hechi prefecture; its administration continued to shift in the early Qing before returning to Oujia Mountain.