Around Marseille, no good beaches but amazing snorkeling in: * the Calanques, see: What are some fun things to do with children (12, 15) in Marseille, France in the summer? read more
The Salagou lake, situated about 50 kilometers west of Montpellier near the village of Clermont L'Herault is really nice. I have been there a lot and the landscape is breathtaking. Advice: When you reach the lake from the Clermont route, don't continue on the road to the left, that's where most tourist go. read more