We just spent 4 wonderful nights camping at San Onofre Bluffs with our 4 and 6 year old children. We brought a wagon to wheel the kids and gear down to the beach (a decent sized hike). The beach was spectacular and not too crowded. Make sure you bring a noise machine because the freeway noise is LOUD at night.

Pros: fantastic beach Cons: noisy, no hookups, spots are very close together with no dividers/privacy