Historical Archive of the City of Cologne up at the site of the collapse (a large hole in the ground), where around 95% of all archival items could be held until August 2011, albeit scattered and in many cases badly damaged. Archive repositories all over Germany offered space to store the damaged and only roughly cleaned documents: wet materials were flash-frozen to prevent mold growth. "Itinerant archivists" worked in the receiving archives all over the country and began the task of re-identifying and re-cataloging. A newly installed centre for restoration and digitization on the outskirts of Cologne started working in 2011, with a total cost for restoring
History of the Jews in Cologne Jewish quarter was rebuilt and the previous inhabitants forgotten. After the destruction of the community during Second World War, the medieval foundations were discovered, among them a synagogue and the monumental Cologne "mikveh" (ritual bath). The archeological survey was conducted after the war by Otto Doppelfeld from 1953 to 1956. On the basis of the awareness of history the area has not been reconstructed after the war and has remained as a square in front of the historical Rathaus. Today, the Jewish quarter is part of the "archeological zone of Cologne". In Cologne there was one of the largest Jewish