Mittelbau-Dora was a Nazi concentration camp located near Nordhausen in Thuringia, Germany. It was established in late summer 1943 as a subcamp of Buchenwald concentration camp, supplying slave labour from many Eastern countries occupied by Germany, for extending the nearby tunnels in the Kohnstein and for manufacturing the V-2 rocket and the V-1 flying bomb. In the summer of 1944, Mittelbau became an independent concentration camp with numerous subcamps of its own. In 1945, most of the surviving inmates were sent on death marches or crammed in trains of box-cars by the SS. On 11 April 1945, US troops freed the remaining prisoners.

From 1933 to 1945, Nazi Germany operated more than a thousand concentration camps, including subcamps on its own territory and in parts of German-occupied Europe.