Sen (river)
The Sen, also known as Sian, is a river in Yakutia, Russia. It is a left hand tributary of the Vilyuy, and is long, with a drainage basin of.
There are no permanent inhabited places in the river area.
Course
The Sen belongs to the upper stretch of the Vilyuy basin. It begins in an area of small lakes of the upper Vilyuy Plateau. In its first stretch it flows across lake Burunda, flowing out of it from the western lakeshore and heading roughly southwards across the plateau. Midway through its course it bends and flows southeastwards for a stretch. In its lower course the Sen bends again southwards meandering strongly in a floodplain with oxbow lakes. Finally, shortly before its mouth it bends westwards and meets the left bank of the Vilyuy from its mouth in the Lena. The confluence is almost opposite the mouth of the Ulakhan-Vava in the facing bank.The main tributaries of the Sen are the long Dzheltuli and the long Saalaa-Yurekh from the left. The river freezes between mid October and late May or early June.