Throughout occupied Europe during the entire course of the Second World War the nazis interned Jews, Sinti and Roma, homosexuals, prisoners of war, mentally disabled people, and political (and non-political) opponents in camps and prisons. The total number of camps in Europe is estimated at 15,000. Some of these, especially extermination camps such as Auschwitz, have been embedded indelibly in the collective European memory. Many others, mainly the smaller camps, have been forgotten by now. By now, most of the camps have been entirely dismantled and destroyed; many places however have commemoration plaques or memorial centres that remind people that a camp was once there. Italy also had concentration camps for imprisoning opponents to the Mussolini regime.