[W, lowland hundred; cf. gwaelod, bottom].
Welsh flood legend of great antiquity usually centring on the realm of Gwyddno Garanhir in what is now Cardigan Bay. In earliest versions of the story the land is called Maes Gwyddno, and is inundated when a well-maiden named Mererid neglects her duties. In the better-known version, dating from the early 16th century, evidencing Netherlandish influence, the legendary king Gwyddno Garanhir reigns over sixteen cities ringed by an embankment with sluices. The drunken dike-keeper Seithenyn neglects his duties and allows the waters to flood the land, drowning all except the king. Yet the bell of Cantre'r Gwaelod's church is still thought to be heard on quiet evenings. The legend is also associated with other points of the Welsh coast, such as Tyno Heylyg further north, and bears striking similarities to the Breton legend of the City of Ys. Modern perceptions of the story are influenced by popular 19th-century retellings in English, such as T. J. Ll. Prichard's poem ‘The Land Beneath the Sea’ (1823) and T. L. Peacock's novel The Misfortunes of Elphin (1829). See also Rachel Bromwich, ‘Cantre'r Gwaelod and Ker-Is’, in The Early Cultures of North-West Europe, ed. Cyril Fox and Bruce Dickens (Cambridge, 1950), 217–41; F. J. North, Sunken Cities (Cardiff, 1957).