Placed in the interiors of Emperor's Castle shows exhibits connected with the Poznań workers' protest against the communist system in June 1956. On the exhibition there are photos of attendants and their personal belongings, and historical sources about the anticommunist opposition between 1945-1989. An interesting thing is a reconstructed tram, used by Protestants as a barricade. admission 4 zł, reduced 2 zł (free Saturdays).