Dachau concentration camp was the first of the Nazi concentration camps opened in Germany, intended to hold political prisoners.
Mauthausen-Gusen concentration camp grew to become a large group of Nazi concentration camps that was built around the villages of Mauthausen and Gusen in Upper Austria.
Sachsenhausen was a Nazi concentration camp in Oranienburg, Germany, used primarily for political prisoners from 1936 to the end of the Third Reich in May 1945.