Hartheim killing centre
The Hartheim killing centre (German: NS-Tötungsanstalt Hartheim, sometimes translated as "Hartheim killing facility" or "Hartheim euthanasia centre") was a killing facility involved in the German Nazi programme known as Aktion T4, in which German citizens deemed mentally or physically unfit were systematically murdered with poison gas. Often, these patients were transferred from other killing facilities such as the Am Spiegelgrund clinic in Vienna.