Sen (river)

The Sen (Сэн; Сээн), also known as Sian (Сян), is a river in Yakutia (Sakha Republic), Russia. It is a left hand tributary of the Vilyuy, and is 181 km long, with a drainage basin of 3510 km2.

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 2044 km 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 53 km long Dzheltuli and the 26 km long Saalaa-Yurekh from the left. The river freezes between mid October and late May or early June.