At the Gross-Rosen concentration camp, the number of subcamps was 97.[2] The Auschwitz camp complex (Auschwitz I, Auschwitz II-Birkenau, and Auschwitz III-Monowitz) had 48 satellite camps; their detailed descriptions are provided by the Auschwitz-Birkenau State Museum.[3][4] Stutthof concentration camp had 40 subcamps officially and as many as 105 subcamps in operation,[4] some as far as Elbląg, Bydgoszcz and Toruń, at a distance of 200 kilometres (120 mi) from the main camp.[6][7] The camp system was one of the key instruments of terror, while at the same time providing necessary labour for the German war economy.