The heart of the old town is the Old Market Square (Alter Markt), with the Gothic Town Hall (13th century). Behind the town hall soars the imposing Nikolaikirche (St. Nicholas’ Church), built in 1270–1360. The square is surrounded by houses from different periods, including the Gothic Wulflamhaus (a 14th-century patrician house, today a restaurant), and the Baroque Commandantenhus of 1751, the old headquarters of the Swedish military commander.