Trier (founded by the Romans - oldest town in Germany). Very fun to stroll the streets or peek into the cathedrals. I saw the robe of Jesus here in 2012. www.RiverCruiseGuru.com for free assistance with your river cruise.
The Heilbronner Portal in Friedenskirche (Church of Peace, Potsdam, Germany) leads from the cloister area to the Maryl Garden. It is a replica of a Romanesque portal at the Heilsbronn monastery in Franconia. The church is part of the palace grounds of Sanssouci Park under the patronnage of King Frederick William IV.