The caravan park is called Pendyffryn Caravan Park and is still there, close to the A55 (which wasn't built then.) It is in a place called Dwygyfylchi, next to Penmaenmawr. The mountain you climbed to get over to Conwy is called Alltwen.
My Nain - Gwendoline Roberts - lived on the top road, opposite this mountain which I climbed every day I was there. For a short time I went to Dwygyfylchi school............