INTRODUCTION 38 13TH CENT. FORTIFICATIONS Of this period is the great Chateau de Coucy (Fig. 30), the circular keep of which M. Viollet-le-Duc justly calls the grandest military structure in Europe. The aspect of this immense keep and the massive towers and walls, when seen from a distance, is most impressive. This castle was built by the Duke Enguerrand in., 1223-30. The plan (from M. Viollet- le-Duc's Dtetionntatre) shows the great extent of the buildings, and the numerous halls and domestic buildings erected round the courtyard, as well as the great towers boldly projected at the angles for the defence of the FIG. 31. Chateau de Coucy. Plan. curtains, everything being on the most gigantic scale (Fig. 31). Here the great round donjon does not profess to be a residence, it is simply a redoubt or last refuge in case of siege. This immense tower is about 95 feet in diameter, and 215 feet high, and the walls are 25 feet in thickness. It is surrounded by a separate ditch, with its chemise or enclosing wall, from which a moveable bridge leads to the entrance door. The interior contains one vast apartment or hall on each floor, and all were vaulted with groined arches, which had a circular aperture in the centre of the vault, through which materials of war might be hoisted to
