The Vorotan, or Bargushad or Bazarchay, is a river in the South Caucasus that is the largest right tributary of the Hakari river. It starts from the northwestern slopes of the Syunik Plateau, from the Tsalk pond and adjacent springs at an altitude of 3,045 m, receives the water of streams flowing from several small ponds, as well as the springs of Gorayk village, then it flows in a southeastern direction through the territory of Sisian and Goris regions. It flows through Armenia for 119 kilometres (74 mi) in a generally south-easterly direction. The river enters Azerbaijan again, flowing for 43 km (27 mi) through the districts of Qubadli and Zangilan. The lower section of the Hakari, from its confluence with the Vorotan until its confluence with the Aras river, is sometimes considered to be part of the Vorotan.

Sisian is a town and the centre of the Sisian Municipality of the Syunik Province in southern Armenia. It is located on both banks of the Vorotan River, at an altitude of 1600 m above sea level, 6 km south of the Yerevan-Meghri highway, at a road distance of 217 km southeast of the capital Yerevan, and 115 km north of the provincial capital Kapan.