We are planning to visit friends in Denmark this Summer taking the car. Looking at the route planner I see we can go via some potentially interesting places in Germany where we could break our journey over one or two nights. Or even detour into the Netherlands. I have no clue about tourism in Holland or Germany but know that there must be some beautiful places to visit on the way there or back. Please could anyone suggest where? We have to DCs aged almost 6 and 4 and a half at proposed time of travel. They are very good in the car so this is not as insane as you might think!