The Zugspitze is known as the "Top of Germany", as it's the highest point of the country. From the top you can see 4 countries (Germany, Italy, Austria & Switzerland). This is a magnificent, gorgeous view. Words cannot do it justice.
To get there, you'd want to catch the Zugspitzbahn train in Garmisch-Partenkirchen. You would take this all the way to the end of the line at the lake Eibsee (you'll need to change trains at one point). From there, you take a lift all the way to the top of the mountain. Up here, in addition to the beautiful views, there are also a few restaurants, which do have pretty good food.
When visiting, definitely allow yourself a good amount of time for travelling (both up and down) as it can take close to an hour each way, and you may be waiting for the trains/trams for a little while.
