At the mouth of the Berchtesgaden National Park, surrounded by the Alps, lies Königssee. This 8 km long, 1250 m wide and 190 m deep lake is a must see while visiting Bavaria.
Since 1909, only electric boats have been allowed to roam the waters of this lake, hence its high drinking water quality. Boat tours are offered, which last about an hour each way, allowing passengers to get off and explore the St. Bartholomae church and Obersee, another lake at the last stop of the tour. The returning boats run quite frequently, but be sure to check the schedule for times, since it's an extremely long hike back to civilization from both stops.
After exploring, the lakefront village offers restaurants with authentic Bavarian food, delicious beer, and the opportunity to unwind before your return trip.
Königssee can best be reached by taking the Deutsche Bahn to Berchtesgaden. Just ask a DB employee or call their offices for further information.