There were different types of Concentration Camps in the Nazi held territories: labor camps, transit camps, and death camps. Some locations contained all three types. The first camp, Dachau, was opened in 1933. By the end of WW II, the Nazis had more than 40, 000 such camps throughout Europe and even North Africa. Jews made up the largest number of prisoners, but other groups such as Communists, homosexuals, mentally and physically disabled, Roma, Senti, Seventh Day Adventist, people of color, political dissidents were also targeted.