Neiße

Lusatian Neisse
River
Nysa near Skerbersdorf, Krauschwitz municipality
Countries	Czech Republic, Poland, Germany
Source	Jizera Mountains
- location	Nová Ves nad Nisou, Liberec Region, Czech Republic
- elevation	655 m (2,149 ft)
- coordinates	50°43′47″N 15°13′44″E / 50.72972°N 15.22889°E / 50.72972; 15.22889
Mouth	Oder
- location	Neißemünde, Brandenburg, Germany
- elevation	32 m (105 ft)
- coordinates	52°4′11″N 14°45′20″E / 52.06972°N 14.75556°E / 52.06972; 14.75556Coordinates: 52°4′11″N 14°45′20″E / 52.06972°N 14.75556°E / 52.06972; 14.75556
Length	252 km (157 mi)
Basin	4,297 km2 (1,659 sq mi)
Discharge
- average	30 m3/s (1,059 cu ft/s)
Oder and Neisse rivers

The Lusatian Neisse (Czech: Lužická Nisa; German: Lausitzer Neiße; Polish: Nysa Łużycka; Upper Sorbian: Łužiska Nysa; Lower Sorbian: Łužyska Nysa), or Western Neisse, is a 252-kilometre (157 mi) long river in Central Europe. It rises in the Jizera Mountains near Nová Ves nad Nisou, Czech Republic, reaching the tripoint with Poland and Germany at Zittau after 54 kilometres (34 mi), and later forming the Polish-German border for a length of 198 kilometres (123 mi). The Lusatian Neisse is a left-bank tributary of the river Oder, into which it flows between Neißemünde-Ratzdorf and Kosarzyn north of the towns of Guben and Gubin.

According to the 1945 Potsdam Agreement in the aftermath of World War II, the river became part of the Polish western border with Germany (the Oder-Neisse line). Being the longest and most notable of the three rivers named Neisse (Neiße) (German) or Nysa (Polish) (the two other rivers being the Eastern Neisse (Polish: Nysa Kłodzka; German: Glatzer Neisse) and Raging Neisse (Polish: Nysa Szalona; German: Wütende Neiße or Jauersche Neiße)), it is simply referred to as the Neisse.