In urban planning, the history of a community is usually reflected in a juxtaposition of different quarters shaped by the spirit of their respective epochs. The fact that there are ensembles from one and the same time in a city, which are to be understood as construction and counter-construction, is a trademark of Berlin, the formerly divided German capital. In particular, there are two listed ensembles for this »double Berlin«: the Karl-Marx-Allee in the eastern part of the city built in the 1950s and the Hansaviertel in the west, which was built in 1957 for the International Building Exhibition.