Hrádek nad Nisou (Czech pronunciation: [ˈɦraːdɛk ˈnad ɲɪsou]; German: Grottau) is a town in Liberec District in the Liberec Region of the Czech Republic. It has about 8,000 inhabitants. The town is located on the Lusatian Neisse River near the state border, at the tripoint of the Czech Republic, Germany and Poland. The historic town centre is well preserved and is protected as an urban monument zone.