We went here a lot when the kids were. ... kids.
It was always well run, with a brilliant beach with rock pools to explore and streams to dam. And the site has an indoor swimming pool.
With kids a pool seems to fulfill every need. And happy kids = phew!
http://www.swallowtree.co.uk.
South West France is brilliant with kids, but perhaps a bit far. We used to break the journey there and back with overnights, and make that part of the adventure. The food used to be very inexpensive with fixed price menu options. And the camp sites have great tents and even better mobile homes. On site you can get chips and chicken etc, plus, again, they have swimming pools.