Néris

The river Neris () or Vilija (Ві́лія from Wilia) 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), at Kaunas, as its main tributary. Its length is . For , after passing through Belarus, the river runs through Lithuania. The Neris connects successive Lithuanian capitals – Kernavė and Vilnius. Along its banks are burial places of the pagan Lithuanians. At from Vilnius there is are old Karmazinai Hillfort and Karmazinai burial mound. The reasons for the dual naming of the river as Neris by the Lithuanians and Viliya (formerly Velja, meaning "big, great" in Slavic) by the Slavs are complex. Even in Vilnius, there are toponyms including both names, e. g. Neris remains in the riverside names of Paneriai and Paneriškės while Velja is a part of the name Valakampiai, which means "an angle of Velja" in Lithuanian. In Kaunas, a part of the city by the Neris river, that was formerly a separate town, is also named Vilijampolė (Vilija + polis, that means "polis by Vilija"). Although it has been suggested that Neris is the primeval name of the river, while the name Viliya is of secondary extraction, the dual naming most probably emerged from the confluence of the rivers Neris (now known as Narač River, leaving Lake Narač) and Velja, in the historical Slavic/Baltic borderland, each ethnos choosing their own name for the river starting at the confluence. It is moreover evidenced by the fact that the name Neris was never used to name the river Velja up to this confluence. Therefore, it has been proposed that the Narač River had in fact been considered the upper reaches of Neris by the Balts in ancient times. The name Neris is of Baltic origin, a cognate of the Lithuanian nerti generally meaning "to dive, swim downstream" as well as "to net, crochet". It is likely that the name had a more general meaning of "flow" or particularly "swift and swirling flow" in early times.