Berchtesgaden sits in Bavaria but belongs to the Salzburg orbit in every practical sense: 45 minutes by direct bus from Salzburg Hauptbahnhof, and no border formality to speak of. The Königssee is one of the most spectacular alpine lakes in the Alps, a deep fjord-like body of water enclosed by 2,000-meter walls. The Obersalzberg above the town was the Nazi leadership's mountain retreat, and the Dokumentationszentrum Obersalzberg is among the most thorough interpretation sites of that period anywhere in the German-speaking world. The Eagle's Nest (Kehlsteinhaus) at 1,834 meters, built as Hitler's birthday gift and now a restaurant open from May to October, is reached by a dedicated mountain road. A full day from Salzburg covers all three.