German Aeronautical Research Institute
The Deutsche Luftfahrtforschungsanstalt (LFA/German Aeronautical Research Institute, also known as the Hermann Göring Research Institute) was a secret German facility for airframe, aeroengine, and aircraft weapons testing during the Second World War. It was located near Völkenrode, on the western outskirts of Braunschweig (Brunswick), near what became the Inner German Border.
Source: Wikipedia — German Aeronautical Research Institute (CC BY-SA 4.0)