A good deal of research and development into the German A4 (aka the V-2) was performed at the Peenemünde Army Research Center. This facility had laboratories, test stands, and (until largely destroyed by Allied bombardment) production facilities.
I present here two maps of Peenemünde.
This first map shows Peenemünde's location on the Usedom Peninsula on the Baltic Sea, including the direction of fire for test launches:
This map is an overview of the entire facility, including the Ordnance Test Area, Ordnance Engineering Center, Ordnance Pilot Production Plant, the the residential communities. Although many locations on this map are numbered, the key to this map unfortunately was not present in the source document, so I am unable to make the key available.