It is worth pointing out now that, for those who want an easier life, suffer from vertigo, or just love Roman roads to the point where they are beyond all reason and help, the Military Way can be followed almost continuously eastwards from here to Housesteads and provides a useful (and less demanding) alternative footpath. It normally shows up as a grassy strip to the south of the curtain wall, usually closer when the going is easy, further away along the craggy bits, and it is clearly marked on the Ordnance Survey 1:25,000 Explorer maps (another good reason to have them with you).
Heading east once more, and leaving Milecastle 42 in our wake, we climb gradually, with Claytonized curtain wall to our left, perched on the edge of Cawfields Crags. John Clayton, who owned this stretch of land during the 19th century, had his workmen consolidate the wall by excavating the tumbled facing stones that lay to either side of it and reconstructing them as coursed drystone walling on top of the surviving in-situ courses. This differed from the preferred Ministry of Works method of ‘as found’ consolidation in later years, but a compromise was reached whereby the newer was combined with the older to preserve the unusual character of the National Trust-owned stretches on top of the more accurate modern approach.
Before long we pass the site of Turret 41b before encountering a small re-entrant at a slight nick, with a gate through the curtain wall. This is Thorny Doors. Immediately afterwards the wall makes an assault on a particularly steep section of the Whin Sill and it is here that the highest surviving piece of curtain wall (as opposed to reconstructed, like the facing at Hare Hill) is to be found. When consolidated, it is said that putlog holes for wooden scaffolding were found in the outer face of the wall and that it was eroded in an unusual manner, perhaps because of the way in which the wind is funnelled through the nick. We can only admire the horizontal coursing of the curtain wall as it seems to ascend the crags effortlessly.
The next undulating stretch soon presents us with the remains of Turret 41a, demolished almost to ground level when the Wall was briefly abandoned when the Antonine Wall was built. The recess within the curtain wall was filled in and the turret never reconstructed. There is another slight turn to a more southerly course and we are soon approaching the site of the old Shield-on-the-Wall farm house, which sat directly on the curtain wall but was later moved slightly to the south (where it still stands, amongst a clump of trees). This is the shallow re-entrant at Caw Gap and a length of ditch duly appears to the north to cover it.
A minor road passes through the gap and, after we cross it, we have a stiff climb ahead of us. The curtain wall to our left has now been replaced by a modern drystone wall on top of it. The climb is fairly relentless and continues all the way to Milecastle 41, but eases off in the latter part.
Milecastle 41 (Melkridge) is a short-axis milecastle that survives as humps and bumps. By now, you are probably counting off your walk in milecastles and beginning to feel a creeping indifference towards them. Be patient: there are still a few treats in store.