We are thinking of exploring 2 European river sections from 2 base cities, one on the Rhine, one on the Danube. And then take day cruise boats, up or down river to take in the scenery, get off at different locations and explore. So, not hotel boats like Viking. Where would be a good base on the Rhine- Koblenz? Where would be a good base on the Danube- Durnstein? We want to walk around, take in the feeling of the places, the scenery, people, not so much to spend lots of time touring castles, etc.
Many thanks