Meersburg Castle dates back to 628 when Dagobert I, the Frankish king, built a military tower on granite overlooking Lake Constance. Features were added to the castle over the years, including the main tower which dates from 1509. The castle has low ceilings and granite floors, as seen in this picture of Knight`s Hall. There are 28 fully furnished rooms, which give the visitor the feeling of everyday life in a medieval castle.