Stp. Tannenberg at the Oberlands was the principle command for the infantry and artillery operating in Guernsey and the Channel Islands. A complex of such size and importance therefore required significant communications infrastructure. Along with the large repeater station, this large bunker in the Quatre Vents estate served to transmit and receive signals across the line, and route calls either to positions round the island, or through submarine cables to the continent. This bunker was one of the most important parts of German military infrastructure on the island. The bunker itself does not have a type number, but is two floors and resembles a type 618. Today it is used as a music studio, and internally altered.