I'm looking for recommendations for travel with 2 boys (12 & 14) from Paris to Barcelona by train in July. We have 3-day France rail passes and tentative itinerary is Paris-Cassis-Carcassonne-Barcelona. We got 3 nights in Paris and 1 in Barcelona already taken care of, but 4 nights between them is still under works. Any recommendations as far as teenager activities and easy access by train?
Also, any feedback for coach surfing in France?