Warsaw concentration camp
Warschau (see other names) was a Nazi concentration camp in German-occupied Poland during World War II. It was formed on the base of the since-demolished Gęsiówka prison, in what is today the Warsaw neighbourhood of Muranów, on the order of Reichsführer-SS Heinrich Himmler. The camp operated from July 1943 to August 1944.
Source: Wikipedia — Warsaw concentration camp (CC BY-SA 4.0)