The Nida [ˈɲida] is a river in central Poland, a left tributary of the Vistula river, into which it flows near Nowy Korczyn). The Nida has a length of 151 kilometres (29th longest) and a basin area of 3,865 km2. This includes the protected area called Nida Landscape Park.The Nida itself is made of two smaller rivers, the White Nida and the Black Nida, which merge in the village of Brzegi (near Checiny). It is a typical lowland river, with little difference in the water level.