17. Colditz Castle was both a mental health asylum and a prison for political prisoners before serving as a prisoner of war facility
Colditz Castle was over 400 years old when it was converted to serve as a sanitarium for both the mentally disturbed and those suffering from tuberculosis beginning in 1829. It continued in that role until 1924, when the disruptions of post-World War I Germany led to its closure. In 1933 the new Nazi government converted the castle to be a prison for political enemies, communists, Jews, and some convicted of petty crimes by the German courts. After the completion of concentration camps most such prisoners were transferred, and in 1939 Colditz became a prisoner of war camp, receiving Poles, Czechs, British and British Empire, and French prisoners.
Although the Germans considered Colditz to be escape proof, several POWs successfully escaped the complex through a variety of daring means. In 1943 the Germans decided to keep only British and American prisoners at the camp. After the war, during which Colditz was liberated by the Americans, it fell under the Soviet zone of occupation. The Soviets used it for a time as a lockup for local criminals and for political dissidents, until the sheer number of uncompleted escape tunnels and hide-outs within the structure forced them to abandon it as a prison. French, Dutch, Polish, Belgian, British, and Indian officers all successfully escaped from Colditz during the war, and many other planned attempts were abandoned as it became clear that the war was nearly over.