Neris basin

thumb|Confluence of the Viliya and Narach River|Narach: a conjectured reason for the dual naming of Neris thumb|Neris near Gediminas Tower in [[Vilnius, Lithuania]] thumb|Confluence of Neman and Neris in Kaunas The river Neris () or Vilija (, ) rises in northern Belarus. It flows westward, passing through Vilnius (Lithuania's capital) and in the south-centre of that country it flows into the Nemunas (Neman) from the right bank, at Kaunas, as its main tributary. Its length is .