deutsche oper berlin. architect: fritz bornemann (1961). what I especially like about this building is the blank, empty main facade. instead of the expected big windows/glass box lobby of the typical modernist theater building, there's - nothing.
(but there are windows, of course: one has to turn the corner, one has to leave the wide bismarckstrasse avenue and enter either one of the two narrower side streets to discover very generous fenestration indeed, symmetrically, on both side street facades.)
More about this spectacular building, here.