south of france

I think you'll need two bases: one for the Riviera and one for Provence. Where you choose to stay will be affected by which towns and other sights you want to see. The latter will also determine how much, if any, need you have for a car. Basically, the coastal towns on the Riviera east of St. Tropez (which itself does not have a station) can be easily reached by train. It takes longer to get up to the hill towns, which will mean using a bus or a car.

You can travel between Avignon, Marseille, Arles and Aix-en-Provence readily by train. The small towns in Provence are trickier. Many do have rail service and/or bus service, but it may not be terribly frequent. And in July, it can be very hot, standing around outdoors waiting for a bus.

I also spent 10 days in the south of France. I spent 3 nights in Nice without a car, which is not really needed, but depends on where else you might want to go while there. Then took the train to Avignon for 1 night, then rented a car for 6 days in Provence, staying in Roussillon.

So, I agree with the other poster that you might need 2 bases depending on which places you want to see. You can do it all by car or a combination of car and train. But I do think some parts of Provence are seen best with a car.

We had a car in Provence in Late April 2017 and we stayed in Arles and had easy access to all of the attractions.Our hotel was on the river with a View of the river and cruise ships.I would stay in Nice as suggested by other posters to explore that area.
Mike

I'm loving all these great ideas. We have decided to do both areas - 5 days or so in each. Thank you. Nancy

I stayed in Arles while in Provence and thought it was a good choice. I wanted to avoid the traffic in and around Avignon. In the Riviera, I stayed in Juan les Pins. I'd recommend there, just west of there, Gulfe Juan, or Antibes. They have nicer beaches and may be less crowded. My favorite was Antibes but I'm wondering if it's too small for July crowds? I turned my car in when I got to the Riviera and used the train up and down the coast. I flew back to Paris from Nice for a few days before flying home.

Do be careful on the Riviera trains. They are worked by pickpockets. Not a reason to avoid the trains, just a reason to pay attention, especially if someone gets into your personal space.