Built between 1285 and 1350 in a potpourri of styles, this cathedral includes a Romanesque 12th-century nave in its southern aisle; chapels from the 14th and 15th centuries; and a 5th-century sarcophagus in the apse. More recent additions include the 18th-century gilt Baroque organ. Acoustics make Gregorian chants (4.30pm Sunday) unforgettable. There are cloister tours.