The Keep is a fine example, dating from 1182, and essentially Norman; it is nearly 100 feet square, and rises to a height of 95 feet. It presents a commanding feature from the sea as the summit is nearly 500 feet above high water. The usual Norman pilaster buttresses are apparent at the angles and in the centres of three of the faces. The Keep walls are of most unusual thickness, in parts exceeding 20 feet, but these are honeycombed by a number of small chambers and passages. Only loopholes admit light to the lower stage, the more important rooms being upon the second floor. The Keep is provided with two wells, not contained, as usual, in the great transverse wall which divides the building into two distinct portions, but in the thickness of the eastern wall. Subsequent defences have taken the form of massive curtains defending the enceinte, which encloses an area of 35 acres, a special feature being the large number of towers, round-fronted or square, which are liberally scattered along it. The general shape now developed may claim to be that of the Concentric Fortress, although it is classified among the Rectangular Keeps. Its adaptation to up-to-date requirements has in many cases led to the obliteration of many ancient features formerly distinguishing it; these, although undoubtedly justifiable, are to be regretted from the antiquarian point of view. In order to convey an idea of the internal economy of a Keep and the disposition of the various apartments the diagram appearing on p. 100 may be of use. It shows the five successive floors of Hedingham Keep, Essex, which dates from about 1140. Upon the ground floor plan the great thickness of the walls, about 12 feet, is plainly apparent with the narrow embrasures giving light. At the base the walls batter slightly for a few feet, not shown on plan. The well-stair commences in the basement and extends to all the floors. The first floor or entrance story has a small round-headed doorway, the arch of which is ornamented with zigzag moulding; steps now lead up the face of the wall to it, but formerly it opened from a forebuilding of which traces still remain. Here the honeycombing of the walls commences which is so marked a feature in Keeps. The embrasures have very narrow openings externally but wider than on the ground floor. The central dividing wall here is pierced by an arch and hence shown dotted in plan. On the second floor is the great Hall of Audience; across the centre is built a remarkably fine arch carried upon Norman shafts with scollop capitals and moulded bases. The fireplace and also the window openings have zigzag mouldings around the circular heads. The upper part of this room has a gallery running round it shown as the third floor plan; the windows are doubled by a dividing pier and openings admit of a view into the Audience Chamber. Above is the fourth floor low in height, with zigzag moulding round the external window heads. Over this story is the flat roof and