Schloss Grafeneck was built in the 16th Century. It became a sanitarium until the Nazis decided to use it as the first T4 site outside of Berlin. Over 10,000 were murdered ther in less than a year, and the gassing expertise gained there was used in the death camps. It is disturbing, not only for the history, but because it is still used as a sanitarium, and the cemetray where they put the cremains in a mass grave is still active. I finished reading Defying Hitler in the shadow of the castle waiting for the bus.