Sian River [Сян (Sjan); Polish: San]. (Map: Sian River.) The largest (right-bank) tributary of the Vistula River originating in the Carpathian Mountains. It is 444 km long and drains a basin area of 16,730 sq km. It flows quickly near its headwaters in the Beskyds. The cities of Peremyshl and Jarosław are situated on it. Although only the source of the river is located in Ukraine itself, the Sian runs for 50 km along the Polish-Ukrainian border and then continues through a large section of Ukrainian ethnic territory in Poland, notably the Sian region.

[This article originally appeared in the Encyclopedia of Ukraine, vol. 5 (1993).]