The domed cathedral (1751) was designed by its Italian architect in the light, ethereal, Renaissance style of his native land, with columns, pilasters, cornices, and balustrades. It was constructed on the site of a 1047-vintage church of the same name that became the Namur cathedral in 1559; the old church's belfry still survives in the existing structure. The Musée Diocésain et Trésor (Diocesan Museum and Treasury), place du Chapitre 1 (tel. 081/44-42-85), just outside the cathedral, holds a small but impressive collection of ecclesiastical relics, gold plates, and sculptures.