If you plan to travel in northern Germany, then I suggest a visit to the North Sea island of Wangerooge. You have to take a ferry to get there, and it's a 40 minute ride, so start heading to the ferry port early. After arriving, don't take the train, but instead follow the road about a mile or so to the youth hostel in the tower. Get a room, and rent a bike from the youth hostel. Explore the island, and come back at 6 for dinner. After dinner, head on down to the main street, grab a few drinks, and go on down to the beach to watch the sunset (see picture). The next morning, get a mud flat tour (make sure you book in advance), and come back in time for breakfast.