The bombing raids of 1943 destroyed 90% of the city center. The city was almost completely rebuilt during the 1950s and is a combination of renovated or reconstructed old buildings and architecture of the 1950s. Outside the city center, the suburbs are dominated by 19th-century architecture. The oldest monument is the Druselturm; the Brüderkirche and the Martinskirche are also, in part, of medieval origin. The towers of the Martinskirche are from the 1950s.