Wall Mile 15 [HB 173]
We continue to descend, following the line of the ditch (it can be a little difficult walking along it in places, since it is a bit like traversng the side of a hill; troublesome things, ditches). We cross a lane (the access road to Whitchester farm) before embarking upon a short jog along a bit of field. Then we have to cross over another road, this time marked by alternating red and white kerb stones; this is the entrance to Albemarle Barracks, the former Ouston airfield.
Our journey continues uphill now, towards Harlow Hill, along the verge next to a not-very-exciting field. Here the Wall is in stealth mode: the ditch is barely discernible, the curtain wall is under the road, and the Vallum shows up only as a cropmark from the air (under the right conditions). But is the curtain wall really there? We saw that it still existed under the road on the outskirts of Heddon-on-the-Wall, but along Wall Mile 15 and at Harlow Hill, where it has been examined by excavation, it has been completely removed (and not necessarily by the original road builders).
Finally, near the crest of Harlow Hill, we reach the likely site of Milecastle 16.
Milecastle 16 (Harlow Hill) [HB 173; haiku]
No trace of this milecastle has ever been noted archaeologically, although antiquarian reports suggest it was once visible. Its prominent location on the hill meant that it would have enjoyed fine views towards Milecastles 17 and 18 to the west and 15 and the fort at Rudchester to the east.