The two adjoining villages of Zossen and Wünsdorf, and the north-south road linking them, were enclosed within a secure military area during WWII, the area is about 33 - 40 km S of Berlin. 

The expected guide did not arrive at this site, and we were unable to see the interiors of the bunkers.  However, we were able to see the massive concrete interiors (now wrecked by deliberate dynamiting) of the fake 'cottages' built to hide bunker entrances, and some of us were able to explore to a small extent below the wreckage.

Two large main bunkers were known as Maybach I and Maybach II - a long tunnel linked them.  The wrecked 'houses' each covered smaller bunkers

The installations (from WWII and the Russians) are described and illustrated in some detail in the following English-language booklet stocked at Amazon.co.uk

Hans George KAMPE, 1996, "The Underground Military Command Bunkers of Zossen, Germany." History of their construction and use by the Wehrmacht and Soviet Army 1937 - 1994. 48pp. Published by Schiffer Military / Aviation History, Atglen, PA, USA. [ISBN 0-7643-0164-0]