A fine 12C and 13C Gothic building with numerous buttresses topped with small and large pinnacles. The interior has particularly full, harmonious proportions. The works of art include a superb, 15C Entombment (in St Sépulcre's chapel) and the statue of Notre-Dame d'Eu attributed to one of the Anguier brothers, Baroque sculptors who lived in Eu in the 17C. The crypt contains the mausolea of the counts of Eu, of the House of Artois (14C and 15C).