Gradlon also gave him a palace on the location where the Quimper Cathedral now stands. After his death, he was buried in front of the altar of the Quimper Cathedral. An abbey was dedicated to him in 1201 by King Philippe Auguste, near Mantes; it was called Saint Corentin Abbey. He is also known in Cornwall, where St. Corentine's Church, Cury is dedicated to him. In the Breton legend of the city of Ys, Corentin is the saint who observed the fall of Ys and warned King Gradlon of the sin committed by his daughter, Dahut (Ahes). The Christianization of the Celts was concurrent with the fall of Rome, and so the mercy of Corentin towards Gradlon symbolized the cultural transition. Prior to Christianity, the Celtic lifestyle was based around estuarine aquaculture dependent upon the pattern of the tides. In lowland environments where flooding is a major hazard, megaliths served as an astronomical calendar to predict the movement of water. Coastal Celts (also called Armoricans) used a system of dikes and locks to provide irrigation on an alternating basis, allowing separate plots of land to switch between producing cereals and shellfish. Corentin is a patron saint of seafood and, through him, inland aquaculture demonstrates the sustainability of Celtic Christianity over prior practices. Later tales blamed the caprice of Princess Dahut for the cataclysm at Ys. Some tales refer to her as a descendant of faeries sent to beguile King Gradlon into ruin. Others depict her as a princess seduced by the devil into opening the floodgates. The tales share a common plot point: King Gradlon and Princess Dahut magically escaping to shore on horseback where they are waylaid by Saint Corentin, (or in some versions Saint Guénolé) who decries the excess of Dahut, causing her to fall into the water and become a morgen or siren. Saint Corentin then absconds to his hermitage while the king embarks on a hunting party. Gradlon becomes lost and hungry enough to request food when he stumbles upon Corentin's hermitage. Corentin offers the king a morsel of his miraculous, regenerative fish, symbolizing the gift of Christianity. He is represented with a whole fish or a half of fish (reminder of the fish he shared with the hunter) that he holds in his hand or at his feet where he is sometimes associated with a fountain.