CARDIGAN BAY, a gulf on the west coast of Wales; along the counties of Cardigan, Merioneth, and Carnarvon, from Cardigan-Head to Braich-y-Pwll. Its length, across the entrance north and south, is 48 miles; its length, from Cardigan-Head to the top of a projection between Merioneth and Carnarvon, north-north-eastward, is 64 miles; and its greatest breadth, from the line of entrance to the mouth of the river Dyfi, eastward, is 30 miles. Part of its bottom is the submerged track of Cantref-Gwaelod, and is there beset by the reefs of Sarn-y-Gynfelyn, Sarn-y-Bwch, and Badrig; but the rest is free from obstacles to navigation, and has a depth of from 3 to 30 fathoms. Bardsey Island studs it in the vicinity of Braich-y-Pwll; and is washed by a strong current setting from the south. The chief harbours are those of Cardigan, Aberayron, Aberystwith, Aberdovey, Barmouth, Mochres, Pwllheli, Portmadoc, and Aberdaron. See Cantref-Gwaelod and Bardsey Island.

(John Marius Wilson, Imperial Gazetteer of England and Wales (1870-72))