I like the region between Boreaux and the coast. It offers warm days and cool evening, more comfortable than the med’. It does rain some times but less than Brittany.
I like the huge beach which has good surf (lacanua ocean and Hourtin Plage). But the waves are better for robust teenagers than younger kids. We camped here pre kids say 25 years ago
http://www.camping-cote-dargent.co.uk/
Very little town and you can walk to the beech
More recently we camped here
http://www.le-tedey.com/campsite-france-gironde.html
This on one of the amazing lakes. So safe warm swimming and water sports. Good water sports rental a short way away, thermal winds give good sailing and windsurfing. You can drive or cycle to the beech to surf. The whole area is well connected with cycle paths
But much as I love it the area is a cultral dessert. No ruins or castles. It just depends what you want. It’s fine for me but less good for my wife