Hello!
My boyfriend and I are flying into Frankfurt 6/26 and need to be in Stuttgart on 6/30 by the evening, so we have about 4 days to sight-see between those two areas. We won't be renting a car, and would prefer to travel by train or maybe bus. We'd like to see a lot, but we're also happy to take our time sightseeing and move at a more casual speed. I'd rather have a very enjoyable less-eventful trip, than be completely exhausted by a non-stop trip.
What are the most interesting (and accessible) sights/towns/landmarks that we should check out along the way?
Thank you!!