Grafeneck is a small rural village in Germany, near the town of Münsingen , south-west of Stuttgart. The castle of Grafeneck, which had been an asylum for crippled people before, was turned into an extermination facility by the Nazis.

During 1940 and 1941 mentally ill people were gassed in Grafeneck with carbon monoxide in the first gas chamber. This was the beginning of the T-4 Euthanasia Program.