Description of the Carn Braich y Dinas, on the Summit of Pen-maen-mawr, in Caernarvonshire. By Governor Pownall. Read at the Society of Antiquaries, Nov. 14, 1771.

“Previous to a tour which I made into the West in the year 1769, I took a minute of the account of the fort on Braich y Dinas in Gibson's Camden, as received from a MS. written in King Charles the 1st’s time by Sir John Wyn of Gwydir.”

“The white line which winds along the cliff of the precipice, describes the parapet-wall built along that cliff, to give security to the road, which runs skirting over it, on a very narrow ledge cleared for the purpose.”

Archaeologia 1771 Vol.III Article XXXIII.pp.303-9.