The legend of Cantre’r Gwaelod, also known as the Lost Hundred, is a tale emerging from the ancient Celtic oral tradition, dating back to the Middle Ages. It tells the story of a wealthy and beautiful land, ruled by Gwyddno Garanhir, which was located beyond today’s Cardigan Bay. At its centre was a splendid city known as Maes Gwyddno, famous for its fertile lands, entrancing music, and remarkable beauty. The welfare of this prosperous city was primarily dependant on a well-engineered dyke; the only protection it had against the wrath of the sea. Every sunset, the gate of the dyke would be closed by an appointed watchman. The one who held this great responsibility was Seithennin, a friend to the king and a man known for his hardy spirit. However, Seithennin had a weakness – he loved to drink, and this vice led to the city’s downfall. One unfortunate night, in midst of his merriment, he forgot to close the gate, and a roaring tide engulfed the city, claiming it and its inhabitants, save for the watchman’s daughter and her suitor, who managed to flee to higher grounds. This tale has an enduring presence in Welsh oral traditions, flourishing in poems, songs, and written works. Even today, at unusually low tide, it is said that one can hear the church bells of Cantre’r Gwaelod tolling beneath the waves, mourning for the sunken city and its inhabitants, lost to the depths forever.