The Lusatian Neisse (Upper Sorbian: Łužiska Nysa; Lower Sorbian: Łužyska Nysa), or Western Neisse, is a 252 km river in northern Central Europe. It rises in the Jizera Mountains, near Nová Ves nad Nisou, at the Czech border becoming the Polish–German border for its remaining 197 km, to flow into the similarly northward-flowing Oder from the left. Its drainage basin covers 4403 km2, of which 2201 km2 is in Poland, the rest is mainly in Germany. The river reaches the tripoint of the three nations by Zittau, a German town/city, after 54 km, leaving the Czech Republic. It is a left-bank tributary of the Oder, into which it flows between Neißemünde-Ratzdorf and Kosarzyn – north of the towns of Guben and Gubin. The river was a motivations to found Gubin as a craftmanship and trading port in the 13th Century. Since the 1945 Potsdam Agreement in the aftermath of World War II, the river has partially demarcated the German-Polish border (along the Oder–Neisse line). The German population east of the river was expelled from Poland to Germany. It is the longest and most watered of the three rivers of its non-adjectival name in both the main languages (the two other rivers being the Eastern Neisse and Raging Neisse (Polish: Nysa Szalona; German: Wütende Neiße or Jauersche Neiße)). It is usually simply referred to as the Neisse.

Name

Since the river runs through the historic region of Lusatia, the adjective "Lusatian" or "Western" before the name of the river Neisse is used whenever differentiating this border river from the Eastern Neisse (Polish: Nysa Kłodzka, German: Glatzer Neisse) and the smaller Raging Neisse (Polish: Nysa Szalona; German: Wütende Neisse or Jauersche Neisse), both in Poland.

Towns and villages

At Bad Muskau the Neisse flows through Muskau Park, a UNESCO World Heritage Site. Cities and towns on the river from source to mouth include:

Tributaries

Right bank: Left bank: