More useful info from the CTC forum:
“We camped here in 2001.
Marshall Meadows Farm
Tel: 01289 307375
The site was basic with no shop, but does have toilets and showers. It also has the main rail line running past it, although we didn’t find it kept kept us awake. It’s situated off the A1 between Berwick and the Scottish border. The site has one really interesting feature. To get down to the beach, you went down a tunnel in the middle of the site, which bring you out halfway down the cliff. You then had to abseil the rest of the way down!The only real downside was that there wasn’t a pub close to hand.”
How cool would it be to camp there, overlooking the sea! Worth considering.