River Flow During Autumn Fall Season. Neris River Second Longest in Lithuania. The Neris or Viliya (Belarusian: Ві́лія, Polish: Wilia) is a river rising in Belarus. It flows through Vilnius (Lithuania) and becomes a tributary of the Neman River (Nemunas) in Kaunas (Lithuania). Its length is 510 km (320 mi).

Confluence of Neman and Neris in Kaunas the river runs through Belarus, where it is called Viliya, and 235 km (146 mi) runs through Lithuania, where it is called Neris.

The Neris connects two old Lithuanian capitals – Kernavė and Vilnius. Along its banks are burial places of the pagan Lithuanians.