Haus des Lehrers by Hermann Henselmann

the building was raised between 1962 and '64 at Alexanderplatz together with the BCC Congress Hall and its beautiful interior..
Hermann Henselmann was THE Architect of the DDR (plans for the Fernsehturm, Stalinallee..)
I particularly like the huge mosaic by Walter Womacka showing the perfect socialist life in bright colours.