from Llamberis climb the road up the hill behind the town driving N.W.Park by the sign for footpath.follow path past small lake ,then past crossing paths and you can see the menhir below easily spotted even in summer .A great place to sit and watch the world turning.return to path and carry on for the battered but recognisable Hafodlas cairn circle.
I can't work out where this 'cromlech' can be, I'm wondering whether it is in fact this stone. If not, it must have been close by (but I can't find one on an old OS map)?
Last summer I came across a native of the neighbourhood of Carnarvon, who told me of a cromlech which interested me[..] The cromlech is called Coetan Arthur, that is to say, Arthur's Quoit, and it stands in the parish of Llanrug, on a hill-slope belonging to a farm called Y Fodlas (i.e., Hafod-las), and about four miles from Carnarvon.
The spot is commonly called Parc Smith, but the proper name of the mountain is Y Cefn Du. The Cefn Du is exposed, especially to winds from the north and the east [..] and it is on the north-eastern corner of it, on the left of Y Fodlas, that the cromlech is to be seen. There used to be two or three meini hirion near it, but my informant does not know whether they are still in situ.
Now, there was a saying which he heard scores of times from old people, that whoever slept under the cromlech through the night of St. John's Festival (Nos dydd Gwyl Ifan) would rise in the morning either a giant in point of strength, or else as weak as a dwarf. Instances used to be adduced to prove it, such as old Ffowe of Ty Du, and Margret 'ch Ifan of Cwmglas, who owed their remarkable strength to the origin here indicated. Others, who were supposed to show traces of the contrary effect of the pernoctation were the Siontwms of the Fuches Las and the Deios of Cwm Brwynog.
My informant does not tell me why the cromlech is called Coetan Arthur, though he intimates that there was a story current which explained it [..]
A letter by John Rhys in Archaeological Cambrensis, January 1888.