You can see the Rhine in a many number of ways. You can do it by car or by train - I've done both, but by far the best way is to do it by boat. The Rhine Cruise is a LONG one, but you can choose to just go for a portion. I docked at Koblenz and got off at Bacharach - about a three-hour duration. Grab one of the many chairs above deck and settle down for a continuing parade of small towns, vineyards, and castle after castle. A warning though: these aren't major huge castles; they're more of the small and cute types. The cruise passed by the famous Lorelei, though from the river, you really can't see anything but rock. It's very relaxing - do wear suntan lotion on a sunny day, because three hours under the strong German tan gave me all the tan I ever wanted.