Over the central gateway, and above the towers, rises a large square turret, which was also vaulted and flagged on the top, and provided with a machicolated parapet. This platform, as well as those over the towers, were thus well adapted to receive the large catapults, mangonels, and other military engines in use in the fourteenth century. The diagonal walls which fill up the angles next the walls of enceinte contained staircases, &c., and are set at an angle so as to present a front against assailants approaching from the flanks. The round wells of the staircases were continued above the roof with round enclosures, which were visible above the parapet in the form of crenellated turrets. [Illustration: FIG. 58. CASTLE OF ST ANDRÉ. _Walls of Enceinte._] The rooms in the gatehouse are well finished in ashlar work, and have ornamental chimneys, of which Fig. 57 is a specimen. That over the entrance gateway contained the apparatus for working the portcullis. These chambers have been used as political prisons at various times; and the unfortunate occupants have relieved their weary hours by carving all kinds of memoranda on the walls and floor, amongst which religious symbols and pictures mingle with armorial bearings, initials, and scraps of verse. These carvings are often well executed, and they form a very interesting, although melancholy exhibition. [Illustration: FIG. 59. GUARD-ROOM ON WALL, ST ANDRÉ.] Some remains of the outer barbican which protected the approach to the gateway may still be observed. The walls of enceinte of St André present some interesting and picturesque details. The great round tower at the south-west angle (Fig. 57) and the plain curtains adjoining it are very characteristic of the period, and have more of a Northern than a Southern aspect. [Illustration: FIG. 60. REMAINS OF A GUARD-ROOM ON WALL, ST ANDRÉ.] The interior of the walls, with their parapets and parapet walks, are in good preservation, and form fine illustrations of these features. In the long stretch of the north wall, in which there are no towers to protect the parapet walks or to contain guard-rooms or posts for reliefs of sentries, small chambers were formed at intervals for that purpose on the top of the wall (Figs. 59, 60). These now present a very quaint appearance, and are suggestive of many a cold and weary watch. They were only large enough to hold half-a-dozen men, but they constituted points which guarded the circulation on the “chemins de rondes.” They were provided with a fireplace and loops to the exterior, and had little spy-holes looking along the parapet walks. The latter are widened towards the interior of the walls with corbelling, and follow the slope of the ground, with steps at intervals. [Illustration: FIG. 61. CHURCH OF VILLENEUVE-LEZ-AVIGNON.]