The concentration camp at Gusen was a place of forced-labour for armaments production and stone-quarrying under the Third Reich. It was one of many sub-camps of the Mauthausen concentration camp. A special company was set up in 1938, Deutsche Erd- und Steinwerke (DESt) to use the labour of the camps. The first industry at Gusen was the quarrying of granite for building stone. During the Second World War quarrying was replaced with work to produce armaments, in underground tunnels as well as on the surface. The Steyr-Daimler-Puch company made parts for rifles. Messerschmitt worked with DESt to make aircraft fuselages. It is believed that at least 70,000 people were enslaved at Gusen and at least 35,000 prisoners died from starvation, disease, exposure or shooting. When the camp was liberated in 1945 there were still 20,000 prisoners. People imprisoned included Jews and opponents of the Nazis from Austria, Germany, Italy and Poland, Republicans from Spain and soldiers from the Soviet Union. Many were brought from other concentration camps to work.
The camp was bombed during the war and afterwards much of it was built over. The visitor centre shows documentation of the camp, including photographs, drawings, written documents and a film with testament by survivors.