Should you be here, not half a mile down the hill from this stone (at SN064383) there is said to be a special well:
A rocky outcrop nearby is called Carn Cwn (Cairn of Dogs). Beneath an overhanging rock is a wishing well. The water is said to rise and fall with the tide and people used to throw pins into it to cure their warts.
Mentioned by Chris Barber in ‘Mysterious Wales’ (1982).
Contemporary local population will have to continue being warty if they depend on that particular well. Had a recce today and it's in a gorsey and overgrown private field with high fencing and walls. Carn of the Dog has nice views but otherwise unremarkable.
You had a look!! That's cool. Disappointing to hear that the locals can't easily visit though. Could take a tiny bit of pressure off the NHS.