The Lusatian Neisse, or Western Neisse, is a 252-kilometre (157 mi) 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 kilometres (122 mi), to flow into the similarly northward-flowing Oder.

Jizera Mountains, or Izera Mountains, are part of the Western Sudetes on the border between the Czech Republic and Poland. The range got its name from the Jizera River, which rises at the southern base of the Smrk massif. The beech forests within the Jizera Mountains were added to the UNESCO World Heritage Site known as Ancient and Primeval Beech Forests of the Carpathians and Other Regions of Europe, because of their outstanding preservation and testimony to the ecological history of Europe since the Last Glacial Period.