In 1952, the GDR abolished its five states [Länder], which had been created in 1946-47. They were replaced with thirteen districts [Bezirke], which were named for their respective seats of power: Rostock, Schwerin, Neubrandenburg, Magdeburg, Potsdam, Frankfurt/Oder, Cottbus, Leipzig, Halle, Erfurt, Suhl, Gera, Karl-Marx-Stadt (Chemnitz), and Dresden. Unlike the former states, these districts had no political independence. Instead, they were "authorities" [Behörden] and were directly subordinate to the party and the national leadership of the GDR. The borders of the new administrative districts were deliberately drawn so as not to be congruent with those of the former states. (East) Berlin did not belong to any district and was considered a special region. Its borders were strictly patrolled – not only the borders with West Berlin, but also those with the GDR districts of Potsdam and Frankfurt/Oder – right up to the building of the Berlin Wall on August 13, 1961. The districts remained in place until the five states were reconstituted in October.