Or try to get to this one - http://www.themodernantiquarian.com/post/36444 - it's just three hundred metres from a tarmac road. Nobody's seen anything like this before. Of course you need to ask permission - no, you haven't seen me - and then the farmers will probably tell you that there's nothing there. That's probably the best way to tell you're getting close to it ! (Ask them where the copper mine is - they should be able to point to it, a mile away. I'm going in there this year with a torch and a ball of string. It forks after a couple of hundred metres - I've been down the righthand (scary earthslips) but never tried the lefthand branch. It is probably contemporary with the mine on Great Orme.