The contour of the ground on which the modern Newcastle stands, is peculiar. It consists of three tongues of land, separated by natural valleys permeated by rivulets. The westernmost of these presents the boldest front to the river, and is that on which the Castle stands; the Skinner-burn bounds it on the west, and the valley of the Lort-burn, the present Dean-street, on the east. The contiguous tongue lies between the Lort-burn and Pandon-dean; and that still further removed, has for its eastern boundary the Ouse-burn. The same natural advantages which recommended the heights of the most westerly of these strips of ground to the Normans for the erection of their stronghold, would no doubt previously induce the Romans to select it as their chief position. They probably enclosed nearly the whole of it within their walls. Horsley, indeed, places his camp in this division, but in the least advantageous part of it, whether considered in a military or in a commercial point of view. The Romans would surely not overlook the importance of the ravine of Dean-street as a defence on the east, especially at a time when the tide flowed up it as far as the Painter-heugh, and of the cliff that descends from the Castle to the river on the south. The necessity of defending the bridge, and commanding the Tyne would not be forgotten. Taking all these things into account, we may fairly suppose the walls of PONS ÆLII to have been thus defined:—The Wall, passing through the site of St. Nicholas’-church, would, of course, be its northern boundary; a line coming from the church, and adapting itself to the crest of the hill that overhangs Dean-street, crossing the Head-of-the-Side and stretching as far as the elevated angle on which the County-courts now stand, will probably mark its eastern boundary; the southern rampart would run from this angle along the edge of the cliff overhanging the Close, as far as the site of the White-friar-tower, which stood at the head of the present Hanover-street; the western wall may have run in the line of the Town-wall as far as Neville-tower, and then have struck up in a straight line to meet the great Wall. Westward of this boundary, the ground slopes down to the Skinner-burn. If these lines are correctly drawn, Roman Newcastle would contain upwards of sixteen acres.