The Oertelsbruch slate quarry
The quarry was used for the testing of the A4 rocket engines. In hardest manual labour the prisoners perpared the site for the armament factory. They had to expand the existing tunnel system for the establishment of the oxygen and nitrogen production. After the war the quarry (and the testing equipment) was used by the Allies. Until 2009 slate mining continued. Today water has filled most of the quarry. Only small concrete fragments of the testing site are still visible.