Beyond this wall lay what was known as Camp III, an extension of the original prisoners’ camp. During the final months of the war it became a site of mass death, systematic mass murder, but also of resistance.

Towards the end of the war, the Mauthausen concentration camp became the destination for large transports from other disbanded concentration camps. This resulted in increased overcrowding and an acute shortage of food. In 1945, on average 200 prisoners per day died in Mauthausen and its subcamps, most due to starvation and the complete lack of any form of medical care. The weak and sick were systematically murdered.

At the end of April 1945, the SS concentrated around 1,400 ill, old and physically weak prisoners in Camp III. They were to be murdered in the gas chamber over the following days. However, fellow prisoners were able to get a large number of them out of Camp III and hide them in other barracks. In this way they saved them from certain death.

After liberation, for a long time Camp III was left to fall into ruin. In 1970, the remaining walls and watchtowers were finally torn down.