Hohensalzburg Castle  is a fortress on top of  the Festungsberg mountain overlooking Salzburg.  It is easily  accessible by funicular which is easier than the 15 min walk up the hill.  The first funicular to the fortress was built  in the 1900s.  The fortress was never taken in war, it was however given up once when Napoleon and his army came knocking.  Salzburg Fortress  is one of the largest medieval castles in Europe, and it is almost 1000 years old.