There is only one concentration camp that is worth visiting in Germany and that is Dachau which is in Munich.  It is the first camp to be set up from the Nazi era.  It stands today as a symbol of inhumanity because of all the horrors that had happened in that camp during the years of Nazi rule.  The camp was liberated April 29, 1945 by allied forces.  The camp only opened to public as a memorial of the dark past in 1968.