We have stayed a few times at one in between Colwyn Bay and Llandudno. Dinas Farm, I think it's called. Smallish, very accessible if you don't drive - a walk or a quick bus from Colwyn Bay station. You can walk to Llandudo or the end of Colwyn Bay beach (what's it called, that bit on the west end? can't remember now). Or you can go up the hill to the Mountain Zoo quite easily from there.
It's not the most exciting campsite, it has a small playground and shower block and that's about it. Very low key. but convenient.