My friends love those river cruises especially because the ships dock right at the foot of town and it’s so easy to walk to things you want to see. That plus almost no kids is a huge plus.Again, I highly recommend European river cruises. Perfect combination of things to do and time to chill on the deck with a drink watching the shoreline for old castles, vineyards, whatever. You get your choice of 2-3 excursions and generally a couple hours to explore on your own before dinner. At least one evening concert off the boat also. Loved all of it.