In reply to Wide_Mouth_Frog:
> Just a warning to everyone - we parked here after the double yellows were painted, but before it was coned off and got a ticket. We were well off the road, but it turns out your can't park either side of double yellows. Who knew!
As a general rule double yellows (or any other parking or waiting restrictions) extend their effect to the building line or other pronounced physical boundary. So you can get a ticket for parking on your own land if you haven't got an obvious boundary feature.
OTOH marking double yellows on the layby was silly - it's not exactly a useful drop-off point, you'd drop off in the Ogwen Cottage car park if you wanted to.
Post edited at 17:41