Somewhere, this has been discussed before (I'll have a look). I can't remember but I think my own conclusion was that at least some of them are in that category you mentioned yesterday - they've got a folkloric explanation that's not really recognised as folklore, because it doesn't involve dragons or saints. There's marks on the rocks but they're older than metal arrow marks.

Or maybe not.

Anyway there's a lot of them about and when you look them up on Coflein it gets very confusing because it's not clear what they are and they are ALL called 'Arrow Stone'.

As for age, all I can say is that they are old as in olde, not that that helps much.

Well worth a visit though if you are doing the Penmaenmawr / Tal y Fan area and strolling down the Roman (whoops!) Road.

What do you think Idwal? Nice pics by the way.

To come back to this, I just chanced upon this paragraph:
"At a late meeting of the Archaeological institute, the Hon. W. O. Stanley gave an account of a remarkable block of stone in one of the mountain passes of Caernarvonshire, which is known as the 'CArreg-y-Saelhan,' or 'the stone of the arrows.' It is a flat stone, nearly circular in form and about six feet over, with a number of straight scorings upon it from a quarter to half-an-inch deep; and these, according to tradition, were produced by the arrows and other weapons of the chieftains, who, on the commencement of war, were accustomed to sharpen them upon this rock."
(from On a Discovery of Flint Arrowheads and Other Stone Implements at Little Salisbury Hill, near Bath, John Evans, Transactions of the Ethnological Society of London, Vol. 4. (1866), pp. 240-243.)

- And it struck me, am I right in thinking that most of these arrow stones are in 'mountain passes'? Are most of them in valleys? (Whereas (please correct me for I haven't a clue) lots of rock art is in more prominent spots?) Could this be significant??