Where best to go in the Summer school holidays?

[GreatGooglyMoogly]

We would like a nice, sandy beach with sea warm enough to swim in, but don't want somewhere too hot/ humid. Also, there need to be enough other things of interest for a 7-10 day stay, eg. towns, shops, scenery, ruins, etc. Our DSs are 3 and 5. TIA

How about Brittany - lovely beaches, not baking hot, lots to see and do - or even the French Alps (filtered bathing lakes with 'beach' areas and grassy picnic places, adventure playgrounds, toddler areas?) Not too hot, fresh air, stunning views see this page and if interesting, drop me a line