|Subject: Towns in France|
Strasbourg is a good home base choice. There are easy train trips to Colmar and Mulhouse (on our own itinerary for September 23-27).
Another possibility for your second town is Lyon, which has wonderful shopping. From Lyon, you can easily do Dijon by train.
You could stay in Avignon with day trips to Nimes, Arles, Aix-En-Provence and Marseille - all by train (and also on our fall itinerary).
You can day-trip to Champagne from Paris; it's about an hour away by train.
About caving, here's an index of the caves in France: http://www.showcaves.com/english/fr/index.html
I love the entry page of this site. Discovery is built into its design: http://www.culture.fr/culture/arcnat/lascaux/en/
Hope that helps, Linda