There are some really lovely sites around barmouth, talybont area. Some right next to the beach, so loads of safe places for the kids to play and lovely rivers walks and mountains etc, the scenery is gorgeous and all the people there are friendly. All different sites, some on farms were you will be woken up by sheep and hens in your field, others right next to the beach, some nothing more than fields with a few trees, and some 5star ones with electricity, lovely facilities and loads to do for the kids.
we've been back there every year for the past 25 or so. Great days out around the area too.