We are now arrived at the most perfect mile-castle remaining on the line, generally named, from the farm-house to the north of it, the Cawfields Castle. The gap which it guarded was denominated by the peripatetic party of 1849, in commemoration of their visit, the Pilgrims’-gap, a name which is beginning to be recognised by the inhabitants of the neighbourhood. [Sidenote: THE CAWFIELDS CASTELLUM.] Until recently, the castellum was nearly covered with its own ruins. Since the annexed drawing was taken, the rubbish has been entirely removed from the inside, as well as the out. The building is a parallelogram, but the corners at its lower side are rounded off. It measures, inside, sixty-three feet from east to west, and forty-nine feet from north to south. The great Wall forms its northern side. The stones used in the construction of this building are of the same size and character as those employed in the Wall itself; the mortar has disappeared from between the courses of the facing-stones, but portions of lime are seen in the grout of the interior. In the western wall, nine courses of stones are standing. The side walls of the castle have not been tied to the great Wall, but have been brought close up to it, and the junction cemented with mortar. [Illustration: H. Burdon Richardson Delt. John Storey, Lith. MILE-CASTLE NEAR CAW-FIELDS Printed by W. Monkhouse York. ] It is provided with a gateway of large dimensions, both on its northern and southern side. In Horsley’s day, it was a matter of doubt whether there was any opening through the Wall, excepting at the points where the Watling-street and the Maiden-way crossed it; the disinterment of this mile-castle sets the question at rest, and justifies us in believing that the passages at Busy-gap, Rapishaw-gap, and other places, are of Roman formation. The gateways are formed of large slabs of rustic masonry, and to give them full development, the walls are thicker here than in other parts. The width of the wall at the lower gateway is nine feet three inches; at the upper, which was, of course, the more exposed, ten feet six inches. The opening of each gateway is ten feet. Two folding-doors have closed the entrance, which, when thrown back, have fallen into recesses prepared for them. Some of the pivot holes of the doors remain, which exhibit a circular chafing, and are slightly tinged with the oxide of iron. The security of the northern gateway did not entirely depend upon the solidity of its masonry, or the strength of its doors. It opens upon a sort of cliff, and the road from it does not lead directly away, but runs for a little distance under the Wall, so as to give an opportunity of more readily acting against an enemy.