The interior is purely ecclesiastical, of the most beautiful type of its time; the grandeur of its dimensions, its structural perfection, and the magnificence of its decoration, are unsurpassed in their way. The exterior is that of a fortress. Its intention is proclaimed by the buttresses rising from the glacis of the base to form, as it were, flanking towers; by the arrangement of the bays, or rather curtains, crowned by an embattled machicolated parapet, which unite these towers, and by the grandiose military character of the architecture. The formidable aspect of the building is much enhanced by the western tower, in effect a donjon keep, completing the system of defence by its connection with the fortifications of the archbishop's palace, which in their turn are carried on to ramparts, crowning the escarpments which, to the north, rise from the Tarn.[21] [21] See "Civil Architecture," Part IV. chap. ii. A few fortified churches still exist--such, for example, as Les Stes. Maries (Bouches du Rhone), which dates from the thirteenth century. Albi was not a solitary instance of this usage. The Churches of Béziers, Narbonne, and many others of the thirteenth and fourteenth century had been surrounded by defensive outworks rendered necessary by religious strife. The buildings thus transformed into strongholds served the further purpose of sheltering fugitive populations in times of panic. One of the most interesting of such examples is the Church of Esnandes, not far from Rochelle, on the creek of Aiguillon, a building which dates from the twelfth century. It was fortified at the beginning of the fifteenth century to resist the incursions of the English. [Illustration: 74. CHURCH OF ESNANDES (CHARENTE INFÉRIEURE). A FORTIFIED CHURCH OF THE FOURTEENTH CENTURY]