There was once a Holy Well set in the wall by the roadside in the area of Rhiw Gwgan, Corris Uchaf, named Ffynnon y Llygaid (Well/Fountain of the Eyes), and it was long reputed to have curative properties. I've now managed to determine that it was destroyed during a road-widening scheme some years ago but, to the best of my knowledge, this the spot where it was. Take a look at the enlargement and you can see where the water still exits.