found: Investigator. A letter to William A. Maddock, Esq. M.P. ... relative to the building of a pier at a cove called Porthdynllaen in Carnarvon Bay, 1807:p. 2, etc. (Holyhead)
found: Statesman's yrbk. world gaz., 1979(Holyhead-Isle of Anglesey, Gwynedd, Wales)
found: Mun. ybk, 1986(Holyhead, County of Gwynedd)
found: GeoNames, algorithmically matched, 2009(ppl; 53°18ʹ22ʺN 004°37ʹ56ʺW)
found: A gazeteer of Welsh place-names, 1958:p. 21 (Holyhead = Caergybi)
found: Wikipedia, viewed 9 March 2016(Holyhead is a town in Anglesey, Wales)