The beginning of the Neris river can be found in Belarus, where the name of the river is Vilija. The Neris is the second longest river in Lithuania. It flows through the two largest Lithuanian cities, Vilnius and Kaunas, and bends around the ancient Lithuanian medieval capital Kernavė. Near Kaunas, it flows into the Nemunas river. The confluence of both rivers has been a strategically important point, therefore Kaunas Castle was built on this site and Kaunas Old Town is located nearby. It is believed that the name of the river is associated with the Lithuanian word nerti, which means to dive.