Travel back in time with an afternoon at Danevirke Museum. There's plenty to uncover here, with interesting displays and exhibits to bring you up to speed on your history classes.
You'll soon see why this Dannewerk collection of historical artifacts is popular with travelers. If you're looking for more to do and see here, Viking Museum Haithabu, Schloss Gottorf, and St. Peter's Cathedral are in this area too. They won't take you long to get to from Danevirke Museum.