this is a DTAG Vermittlungsstelle
tag telecom=exchange

as seen in:
https://www.youtube.com/watch?v=rmMvc4m3o0k

bing maps:
50,222842, 6,660797

other source:
http://db0fhn.efi.fh-nuernberg.de/~dg8ygz/PDF/hvt-schnittstellen.pdf page 96 4th entry