According to Coflein this cairn, on the part of the mountain called the Llorfa, is nine metres in diameter.
A man who lived at Ystradgynlais, in Brecknockshire, going out one day to look after his cattle and sheep on the mountain, disappeared. In about three weeks, after search had been made in vain for him and his wife had given him up for dead, he came home. His wife asked him where he had been for the past three weeks. "Three weeks! Is it three weeks you call three hours?" said he. Pressed to say where he had been, he told her he had been playing on his flute (which he usually took with him on the mountain) at the Llorfa, a spot near the Van Pool, when he was surrounded at a distance by little beings like men, who closed nearer and nearer to him until they became a very small circle. They sang and danced, and so affected him that he quite lost himself. They offered him some small cakes to eat, of which he partook; and he had never enjoyed himself so well in his life.