There is an Iron Age hillfort atop this rock promontory that is one of the most popular places to visit in Wales. There is a simply fantastic bit of folklore attached to the site. Directly from Marie Trevelyan’s Folk-lore and Folk-stories of Wales it is told:
The story of Craig-y-Dinas, in the Vale of Neath, is well known. A version of it appears in ” Glimpses of Welsh Life and Character, published by Mr. John Hogg, London.
A Welsh drover accustomed to attend Barnet Fair stood to rest on London Bridge. He leaned on his strong hazel-stick, similar to those used by drovers in the present day. He was very tired after the long march from Wales, and presently left the bridge for an eating-house on the other side of the Thames. There he was joined by a queer looking stranger, who asked where he got his stick. The drover replied that it grew near his home. The stranger then said the stick must have grown on a spot where treasures of metal, gold, and silver could be found. He offered to make the drover the master of much treasure if he would take him to the spot where the stick grew. To this the Welshman agreed, and the next morning they started for Wales.
In the morning after their arrival at the drover’s home, the stranger accompanied his host to the grassy hollow on Craig-y-Dinas where the hazel grew from which the long stick had been cut. The stranger then said that in a dream he had seen the hollow before, and directed the drover to get a spade and pick, and dig as he directed. The Welshman at once began to dig up the roots of the hazel, and after digging for some time the men discovered a very broad and flat stone. Underneath the stone there was a flight of broken steps, where the men descended, and soon reached a long corridor, from the roof of which a huge bell was suspended. The stranger warned the drover never to touch the bell, for the consequences would be dreadful.
They went on until a vast cavern was reached. It was filled with warriors in shining armour, with shields beside them and swords unsheathed. In the midst of these warriors a circle of twelve knights surrounded a King, and all the men were asleep. The stranger told the drover that these warriors were King Arthur and his knights and squires. They were waiting there until the Black Eagle and the Golden Eagle should go to war. The clamour of the eagle’s warfare would make the earth tremble, and cause the bell to ring so loudly that the warriors would awaken, and go forth with King Arthur to destroy all the enemies of the Cymry, and establish the King’s rule again in Britain. But terrible would be the results if a false alarm ever rang.
In the midst of the space where the King slept were several heaps of gold, silver, and precious stones. The stranger told the drover that he was at liberty to take as much as he could carry from one heap at a time, but the precious metals and stones were not to be mixed. The drover did as he was bidden, and when the stranger ascended, he said “Beware you never touch the bell. But if by chance you do, one of the sleepers will lift his head, and ask, ‘Is it day ?’ and in peril of your life you must answer, ‘It is not day; sleep thou on.'”
The stranger went away, and the drover never saw him again. Many times in the next few years the drover visited the cavern and brought away treasure, so that he became exceedingly rich. Twice he chanced to touch the magic bell, and one of the warriors on each occasion asked “Is it day?” and the drover answered, ” It is not day; sleep thou on.”
One day he eagerly endeavoured to carry away a larger quantity of treasure than usual, and accidentally touched the bell. One of the warriors cried out, “Is it day?” Too excited in his greed for gain, the drover forgot to reply, whereupon, quick and angrily, the warriors took the treasure away from the man. Then they dragged and beat him, and finally threw him out of the cavern, triumphantly drawing the stone over the entrance. The drover never recovered from the effects of the beating, and although he often went to Craig-y-Dinas to search for the spot where the stone covered the entrance to the cavern, he never found it
It is also supposedly a site connected with a Faerie Court and even though Wirk Sikes relates this in his book British Goblins, he seems to think the entire thing a lie. Though there is no reason he gives as to why he thinks so:
Especially does a certain steep and rugged crag [in the Vale of Neath] called Craig y Ddinas, bear a distinctly awful reputation as a stronghold of the fairy tribe. Its caves and crevices have been their favourite haunt for many centuries, and upon this rock was held the court of the last fairies who have ever appeared in Wales*. Needless to say there are men still living who remember the visits of the fairies to Craig y Ddinas, although they aver the little folk are no longer seen there. It is a common remark that the Methodists drove them away, indeed there are numberless stories which show the fairies to have been animated, when they were still numerous in Wales, by a cordial antipathy for all dissenting preachers. In this antipathy, it may be here observed, teetotalers were included.
*Don’t take this to heart as it is an obvious lie. Quote from Sykes’s ‘British Goblins’, 1880.