The tunnel facilities are an integral part of the camp grounds. After the Soviet military authorities had the entrances blasted in 1947/48, the underground facilities were sealed for several decades. The tunnel system has been accessible once again since 1995 through a newly driven tunnel. As few changes as possible have been made to the state of the tunnels as found at that time. Destroyed factory installations, production remnants and fallen rocks cover the floors of the former assembly chambers in wild disarray. Parts of the tunnel facilities have been flooded by groundwater.