On Berchtesgaden underground tunnels

When in Vermont recently I was going through some family items, including those from the military service of my father's uncle Harry Zendran.  Among the more interesting items was the briefing book issued to him and others serving in the american military who were posted to Berchtesgaden in 1945 in order to occupy it

Notice the mention of the underground tunnels and regions, demonstrating in all probability that the allied occupying forces had knowledge of underground areas in use by the nazis, which in all probability was the reason hitler had the berghof built at that location, and those underground facilities may be in use today, including by nazi groups.