Strasbourg/Kehl is an interesting mix of 20th century history, from the European parliament to the old city, and of course the Europa Bridge over the Rhine.
For slightly less touristy areas, Neuf-Brisach, south of Strasbourg is an almost intact Vauban star fortress, built to replace the fortress in Breisach on the German side of the river. The Original Breisach is in Germany, built on a plug of rock and has a bonsai cathedral on the top from which you can see all across the Rhine valley. The two towns are twinned now and there's a lot of monuments and other material about the reconciliation between France and Germany.
Breisach is the centre of the wine growing region of the Kaiserstühl, which is a large extinct volcano in the middle of the valley, and all the villages to the south of the hills are wine growing villages. To the north of the Kaiserstühl the main town is Endingen am Kaiserstühl which has a pretty centre and is also a wine growing town. These areas are popular with locals and German and French tourists but I've hardly ever seen any British speakers there.
There's a museum ostensibly about the Maginot line in
Marckolsheim but I wasn't overly impressed because most of the visible exhibits were US military vehicles that never saw action near the place. There's also a canal between Strasbourg and Neuf-Brisach with some casements and pill boxes by the towpath, which had been converted into a long distance cycling and walking route.
Of course I'm going to plug Freiburg im Breisgau, and the Breisgau region because apart from being astonishingly beautiful it's a cycling paradise with a Mediterranean climate, lots of long distance routes and great cycling provision in the city and friendly locals for the most part on both sides of the border, but then I would say that.
Also I can recommend a good bike workshop in Emmendingen; but I would say that too...
I'll try and dig up some pictures tomorrow if you're interested. I haven't made Strasbourg (yet) but I've covered a few K's in the region.