We are taking a cruise from Barcelona to Venice and will arrive in Venice the morning of October 24. We will have 10 additional days to play. We have been to Germany previously but were up around Cologne. We would like to try to see some castles and other sights which would be within driving distance from Venice and then end up back in Venice when we fly out on Nov. 3. I am looking for suggestions of "must see" sights in southern Germany and even Austria. Thanks.