I have great memories of the Provence region - towns like Avignon, Arles, Aix, etc. If you go during the spring (like May or June), the entire region is stunningly gorgeous and a bike ride could be fun. Avignon has the Palais de Papes and some great history as well as the Chateau neuf de Papes vineyard. Arles has some history with Van Gogh and a roman coliseum. Nimes also has some great history.

I wish I would have been able to visit the Chateau d'if near Marseille (jail/fortress from Count of Monte Cristo fame).

The Calunques (a series of inlets on the Mediterranean) are also very beautiful.

I was also impressed with Monaco and how clean and beautiful it was.

I also loved the train rides along the coast from Nice to Marseille.