Even though the original Afon Ganol is now just a meandering waterway and ditch, in part diverted and culverted, it still retains the distinction of forming the boundary between the county of Caernarvonshire, created by Edward I at the
Statute of Rhuddan in 1284 and the neighbouring lordship of Denbigh,
Now back to the point of the original question, was Rhos Fynach in Caernarfonshire or was it in Denbighshire? Also the reason why you think that it was in that county