I’ve been to 25 different towns in southern France, now I want to see the northern part of the country. I’ve been to Paris 5 times, so please come up with something else (although I plan to spend a few days there before returning home). I’ve also gone on day-trips to Chartres and Giverney. I’m mostly interested in architecture (especially cathedrals), the arts (especially music and art history), general history (especially ancient ruins) and interesting scenery. I don’t care so much about expensive dining, wine or nightlife. I’ll probably be going for something like 2.5 weeks, in August, traveling by rail, not driving. And my partner may or may not accompany me.
Have you considered Britanny?
What about a tour in Alsace ? First pass by Reims which has a cathedral and a nice roman abbey. From there go to Strasbourg and Colmar (Colmar is very charming), and some small other towns.
I would recommend Brittany and/or Alsace regions. Both have a lot of very nice cities and fantastic scenery in the countryside. But you will not find very larges cities there. Cities like Strasbourg, Colmar or Concarneau and Quimpert in Britanny are rather small and you will have been through them in one or two days, so you should be ready to travel a lot from place to place. You could also settle for some more days in a city, get a bike and explore the countryside.
If you go to Britanny, plan your transportation ahead. The middle of Britanny is rather empty and train connections between northern and southern parts can be scarce.
Here’s a suggested itinerary. The cathedral at St. Denis was supposedly the first gothic cathedral ever built.
St. Malo. Lovely walled city on the seaside.