The Zugspitze ist the highest mountain in Germany, even when half of the mountain lies in Austria. I always wanted to go there and I have to say, the view was spectacular. A big white wall of clouds. Anyway, the Eibsee in front of it is a nice thing on its own. The main trip went further into Austria: the Salzburgerland. There are many little lakes and the famous town Hallstadt. I would not recommend it because of the many tourists. Rather go up to one of the many mountains, like the Dachstein, and enjoy an amazing view from the top!