The Basilica of San Martiño de Mondoñedo is considered the oldest cathedral in Spain; it was the seat of two bishops in the 9th century. The current church, of Romanesque architecture, dates from the late 11th century; it was reinforced with buttresses during the 18th century.
References:The Château du Lude is one of the many great châteaux of the Loire Valley in France. Le Lude is the most northerly château of the Loire Valley and one of the last important historic castles in France, still inhabited by the same family for the last 260 years. The château is testimony to four centuries of French architecture, as a stronghold transformed into an elegant house during the Renaissance and the 18th century. The monument is located in the valley of Le Loir. Its gardens have evolved throughout the centuries.