The first Nazi camps were erected in Germany in March 1933 to hold and torture political opponents and union organizers. The role of the camps were expanded to holding so-called "racially undesirable elements" of German society, such as Jews, criminals, homosexuals and Roma. The term "concentration camp" is often used to refer to extermination camps, which were established for the industrial-scale mass murder of Jews in gas chambers. The number of people in Nazi concentration camps peaked at 715,000 in January 1945. This is a collection of DW's content on the concentration camps.