There is Chateau les Carasses in the Languedoc Roussillon region in France. You can rent a house, a maisonette et they have pool on site, plus restaurant, a kids'club, a bowl area, etc..
We stayed there on their first summer opening. You are not exactly on the beach (about 40' to the nearest one) but there are lots of great villages to explore and you can just relax by the pool if you want to.
I haven't been but Borgo Egnazia is also built around the concept of villas that you can rent and yet have restaurant, kids'club etc.. on site.
The other one that comes up again and again and you would probably have great weather is Anassa in Cyprus.
Hope it helps
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