St Mary's Cathedral is gothic in style and built using locally-sourced white and red stone on the site of a Romanesque cathedral which was destroyed by fire in 1258. Situated in the heart of the historic centre of Bayonne on a mound overlooking the Nive and Adour rivers, the cathedral contains relics of St Leo (St Léon in French), a 9th century Bishop of Bayonne and was listed as a World Heritage Site in 1998 as part of the French Pilgrim Routes of Santiago de Compostela. The adjoining cloister dates back to 1240.
Constructed in stages between the 13th and 16th centuries, it was not until a major operation led by Boeswillwald a pupil of Viollet-Le-Duc that the 85m high spires were completed in the 19th century giving the cathedral the elegant outline it retains today.
The chapels are decorated with 14th century style paintings by Steinhel and the stained glass windows are done in the style of Chartres Cathedral.