The stately neo-Renaissance structure across from the Martin-Gropius-Bau, technically placing it in Mitte, has been a political power nexus since its late-19th-century days as the house of the Prussian parliament. Under the Nazis, it went through a stint as a courthouse before being turned into an air force officers’ club. Since reunification, it has been the seat of Berlin’s state parliament. Free changing exhibits are held in the foyer and on the mezzanine level.