 The 1987 National Eisteddfod was held in Porthmadog.It includes the nearby villages of Borth-y-Gest, Morfa Bychan and Tremadog.Porthmadog came into existence after William Madocks built a sea wall, the "Cob", between 1808 and 1811, to reclaim a large proportion of Traeth Mawr from the sea for agricultural use.