Auschwitz-Birkenau is the best-known of the concentration and extermination camps operated by Nazi Germany during the Holocaust. It was the site of at least 1.1 million deaths, predominantly of Jews, but also of Romani people, Poles, Soviet prisoners of war, and gay men. The camp was liberated on January 27, 1945, and has been the site of a museum and memorial since 1947. Today it receives over 2 million visitors per year.