Ok, if you google Aberystwyth caravan sites you should get a few. The Aberystwyth holiday village is in the centre and seems to have good facilities. There are others around the place, like Devil's Bridge which is farther from the sea. There are lots of forestry commission woods around with walks, like Nant y arian and the Hafod. Clarach also has a few sites but they do look quite busy. Tourist info online will have good stuff I think, and you could google Llangranog which is a lovely seaside village where they are caravan parks. Aberaeron is also nice as a base and is right on the sea. Hope they are a bit useful and good luck.