Well, I'm sure this story must relate to the landmarks round here, but I'm not sure exactly which is what. I can't see the stone on Coflein either - I wonder if it's still about.
There is an erect stone, of the class called Maen hir by antiquaries, on a field near Llymysten (see drawing). There is no inscription on it. It has been broken, and there are large fragments lying around. Judging from the diameter of the fragment now standing, its original height would not exceed nine or ten feet.
The tradition in the neighbourhood respecting the stone is, that it was thrown there by a giant from the top of a hill called Gogerddan, more than a mile distant. This giant, and another, his neighbour, who dwelt on the top of a hill called Esgair, near Llymysten, fell out, and had recourse to hostilities in a way worthy of giants, by throwing huge masses of rocks to each other, from the tops of the hills upon which they dwelt. The giant on the top of Esgair threw an immense stone to his antagonist, called Maen llwyd, which is yet remembered by many of the inhabitants, lying in a field near the turnpike road below Garthbeibio Church, and it is said that marks of the giant's fingers were plainly seen on it, shewing with what force he had grasped it. The stone has now been unfortunately broken up and used to erect a wall, and the truth of this assertion cannot be brought to the test by those who doubt it. Both these giants seem, however, to have over-rated their strength, as the stones fell short of the mark in each case, and lay harmless on the plain at a distance from the hills to which they had been directed. Another large stone, thrown, as the tradition is, from the top of a hill on the other side of the valley by a giant, lies now in a hollow on the mountain near a place called Pren Croes.