In the construction of the fortress, advantage was taken of a knoll of the lower or grey chalk, roughly oval in figure, and about 120 feet high above the river. This was levelled on the top and scarped round the sides so as to form a more or less rounded area, 560 feet north and south, by 280 feet east and west. The scarp descended above 180 feet at an angle of 45 feet, or a slope of one to one, into a ditch about 20 feet wide at the bottom, and the opposite side of which, or counterscarp, rose about 40 feet at a similar angle, so that the ditch at the counterscarp level was 100 feet broad, and the crest of the scarp rose 30 feet to 40 feet above the ground opposite. A very formidable defence. Towards the east, where the ground was low, the counterscarp was not above 20 feet high, and to add to the depth of the ditch, it was crested by a light bank, from which the ground sloped towards the marsh. On the north and north-west, where the ditch was at its deepest, and the ground was high, the slope outwards is gentle, falling off for a furlong or so. To the west, where there is a valley now occupied by the railway, the ground is low, and here the outer side of the ditch, forming the crest of the counterscarp, is a narrow ridge, as at Arques, succeeded by a very steep slope. Thus those who approached the place on that side, after toiling up a steep and dangerous ascent, would only find themselves on the outer edge of a deep ditch, with a second still higher and steeper ascent beyond it. Towards the south the ditch crosses instead of skirting the hill, and is much less deep. Here was the entrance, and upon the small tail of the knoll thus cut off is placed the parish church, standing, therefore, just outside the ditch, and in its turn defended by the slope of the hill, and by a hollow way which runs a few yards within the edge of the marsh, the level of which is 8 feet or 10 feet below it. [Illustration: CROSS SECTION BRAMBER CASTLE. _Face p. 268, Vol. I._ ] Upon the table summit, 160 feet from its northern, and 40 feet from its eastern, margin, was thrown up a conical mound, about 40 feet high, and 70 feet diameter at its summit. It is wholly artificial, and the material has evidently been scooped up from the surface of the area, which has thus been rendered slightly hollow, the surface rising gently towards the mound, and towards the outer margin of the area, that is, the crest of the scarp. The mound does not appear to have had any ditch proper to itself. It has been dug into and disfigured on its southern side. Possibly there have been buildings there. On the north the original and usual form is untouched. The slope is very steep. This was the “burgh” or keep of the original fortress.