Grand Circle Tours' 14-day river cruise on the Danube, Main and Rhine rivers started in Vienna, Austria, traveled through Germany and ended in Amsterdam.  Super trip, extremely well organized, great facilities, unbelievably good food and superior guides. The price was very reasonable.  Weather was excellent except for being pretty warm.  Saw and did a lot.  We lived in Germany for 3 years back in the mid-60's and this was our first trip back.  Changes, of course.  One of our guides said,  "There's your embassy in this town and pointed towards a McDonald's."  Oh, my.  Oh, well . . .  Anyway, we enjoyed it, got more than our monies'-worth and are glad we went.   If you're into river cruises, this one with GCT is highly recommended!