We are flying into Cologne late 11/14. We plan to do the markets in Cologne and surrounding 11/19 and after. This leave us 4-5 days to explore somewhere else. Where would everyone suggest? We do not plan on renting a car. We have looked at doing Munich, Brugge/Brussels, or even the Austrian Lake District. We considered Paris because of the train accessibility, but have already been there so want to go someone new. We like to do outdoor things like hiking, although we understand a lot of that may be not accessible because of the season/daylight. We would appreciate any ideas!
South of Cologne on the Rhine River: Hike the Rhine Castle trail (Rheinburgenweg) and the Rheinsteig on the opposite riverbank.
This section of the Rheinburgenweg between St Goar and Oberwesel is terrific.
You might stay in Boppard, the largest of the small Rhine towns in this area, which offers free train transportation around the Rhine and Mosel for all guests who stay there with the VRM Guest Ticket... or perhaps book in Koblenz if you require city comforts. That said, Koblenz is only a 15-minute train ride from Boppard, so it's easy to pop into Koblenz as needed from a Boppard base.