The history of this fine edifice began in the 13C with the construction of the chancel. The transept and the nave were added in the 15C. The luminous, Flamboyant Gothic style of Saint-Corentin Cathedral has been superbly restored, as have the multi-coloured stone facing and pillars. The cathedral boasts a remarkable collection of 15C stained-glass windows, also restored. Between the spires, you can see the statue of King Gradlon on horseback, legendary sovereign of Ys.