Seaview the caravan club site at Spittal is just across the river estuary from Berwick upon Tweed and has good sea views across to Holy Island. It is about a 20min. walk into Berwick. We found the toilet facilities excellent up to the caravan clubs usual high standards. We enjoyed our weekend there and would recomend it to others.We stayed there in a caravan but it does say open to non-members and tent campers.
We stayed at Seaview in September this year. The railwayline is directly behind the site, but trains don't run during the night. We were a little put off by the drive through the estate to reach it, not the prettiest, but it's an easy walk into Berwick and there are sea views from the site which is terraced. Others in the area are Ord House and Marshalls Meadows but I can't comment on these as we didn't check them out.
We then travelled down the coast and I can recommend Proctors Steads Farm at Craster. Banburgh and Dunstenburgh castles are also worth a visit if you get the chance.
If your after a cheap and quiet site, try Marshall Meadows. 2 mins from tesco on north side of Berwick. small site at rear of farm, right on cliff edge very quiet facilities acceptable.
Good Sunday lunch at Ord House when I was there ,but the part I was pitched on was waterlogged,and we had a pair of drunken old idiots blasting song from the 70s all day and night from their caravan till I phoned the warden at 12midnight and he came round and told them to shut up, but It may of been a one off ,I would go back but watch out for soggy ground if you do.
Barns Ness is another one, Caravan and camping Club site next to the BArns Ness Lighthouse, nice an Quiet and yet popular with many folks who wish to visit the East coast.