Craig y Dinas / Dinas Rock, Pontneddfechan, Wales
Incident period: Undated cave legend; nineteenth-century versions collected by Rhys
A stick cut in Wales is recognised on London Bridge as the key to an underground treasure. Beneath its hazel root lie sleeping warriors, heaps of precious metal and a bell which must not ring. The Craig y Dinas story is about more than hidden gold: its tellers disagree over which hill conceals the cave and which leader waits inside.
The stranger on London Bridge
John Rhys reproduces a tale attributed to Iolo Morgannwg through Elijah Waring’s Recollections and Anecdotes of Edward Williams, published in 1850. A Welshman walking over London Bridge carries a neat hazel staff. An English stranger stops him and asks where he obtained it.
The stranger says the wood grew over a treasure and offers to show him how to obtain it. The Welshman is suspicious of the man’s knowledge, regarding him as a conjurer whose help may be dangerous. He eventually agrees to return to Wales and identify the place where he cut the stick.
The root, the stone and the entrance
At Craig y Dinas they dig up the hazel and find a broad flat stone. Beneath it is the entrance to a cavern. A bell hangs in the passage, and the guide warns his companion not to touch it. Further inside, warriors sleep in a great circle with their heads facing outwards.
Their weapons lie ready at hand. The polished armour and arms provide the cavern’s extraordinary illumination, so the visitors can see a distinguished leader with a gold crown and costly equipment beside him. The sleeping company is not presented as abandoned skeletons: its members are waiting for a signal to rise.
Gold, silver and the answer to the question
Two heaps occupy the centre, one gold and one silver. The visitor may take as much as he can carry from either, but must not mix them. His guide takes nothing, explaining that knowledge matters more to him than wealth. The Welshman loads himself with gold.
There is a second instruction. If he strikes the bell and a warrior asks whether it is day, he must answer immediately that it is not and tell the sleeper to rest. On the way out his heavy load causes him to touch the bell. He remembers the answer, the warrior lies down again and the pair escape with the treasure.
Arthur’s army and the promised return
The guide identifies the crowned sleeper as Arthur. His followers are to awaken when the conflict of the Black Eagle and Golden Eagle shakes the earth and rings the bell. They will defeat the enemies of the Cymry, restore their rule in Britain and establish a just government at Caerlleon.
That promised awakening gives the underground scene a political horizon. The treasure is available to a passing individual, but the army is reserved for a much greater moment. The distinction also explains why the guide’s instructions matter: an accidental bell must not be allowed to start the final return.
The second visit goes wrong
Before parting, the conjurer advises prudence and says the wealth should last a lifetime. If poverty returns, the man may visit the cave again, provided he obeys the same rules. He spends his fortune and eventually goes back without the guide.
Again he takes too much. This time, when the bell rings, exhaustion and terror prevent him from giving the answer. Warriors rise, take away the gold and beat him before throwing him outside. The stone closes behind him. He survives with lasting injuries and poverty, and neither he nor later companions can find the entrance again.
Which Craig y Dinas, and which sleeping leader?
Rhys does not conceal the geographical difficulty. Iolo’s note mentions more than one hill bearing the name, including places in Glamorgan and another near Carmarthen. In one district the tale was assigned to the other. A modern map which silently chooses one and calls it the authenticated entrance would lose that uncertainty.
Taliesin Williams, Iolo’s son, associated the cave with the Craig y Dinas on the Glamorgan–Brecknockshire border. Rhys’s correspondent Reynolds agreed, describing the bold rocky height near Pontneddfechan at the head of the Neath valley. This is the locality used for the UKPX area pin.
Reynolds also preserved a different line of transmission. His mother had heard the story in childhood from an elderly woman known as Mari Shencin y Clochyd. In that telling the sleeping leader was Owain Lawgoch, not Arthur. Rhys therefore records a genuine variation in the tale’s remembered hero rather than treating every version as identical.
A cave tradition within a real landscape
Other stories compared by Rhys bring farmers, strange guides, bells and waiting companies into different Welsh settings. Those comparisons help explain the travelling shape of the narrative. They should not be added as further eyewitness visits to this particular hill or used to multiply one legend into several local discoveries.
Dinas Rock is also a place with real geological and industrial history. That history does not identify the treasure chamber. The map reference marks the rocky locality associated with the Pontneddfechan version; it is not an invitation to search mine workings or move stones. The case’s richest surviving evidence is the record of how one hidden army could wait under several hills, with different communities recognising a different leader.
Timeline
Undated legendary setting — London Bridge meeting, first cave visit and failed return.
1850 — Waring publishes the tale attributed to Iolo Morgannwg.
1858 — a Welsh version appears in the Brython.
Nineteenth-century recollections — Taliesin Williams and Reynolds associate the tale with Pontneddfechan; another version names Owain Lawgoch.
1901 — Rhys prints the narrative and compares its locations and leaders.
Sources & further reading
John Rhys, Celtic Folklore: Welsh and Manx, volume 2, cave and sleeping-warrior discussion — Full Waring/Iolo narrative and Rhys’s geographical notes read; the locations and alternative leader remain distinct.
Bannau Brycheiniog / Brecon Beacons, Pontneddfechan walk leaflet — Geographical reference identifying Dinas Rock / Craig y Ddinas and its map grid, not evidence of a hidden army.
Related case files
Dinas Emrys: the falling fortress, the buried dragons and the boy who answered the king
Dobb Park Lodge: the speaking black dog, the burning glass and the unopened treasure
Location note: Dinas Rock locality reference from the National Park’s SN 911 079 grid point, not a cave entrance. Rhys discusses several hills with the same name.
UKPX historical case file. Researched and checked 4 November 2026. Explore the UK case map · Links & Sources.