From the west side of Greenhead, at a terrace of redbrick cottages where the Pennine Way is picked up continue forward leaving the road at a gate beside the cottages, crossing the Newcastle–Carlisle railway line and a footbridge over a little burn and then following an old hedge-line beside the Tipalt Burn. The stream is attractive, lined with sallows and sycamore beneath which grow primroses, anemones and butterbur. The pasture to the left is usually inhabited by an assortment of sheep breeds, including local specialties such as the Border Leicester. Hadrian’s Wall crossed the gap of the Tipalt Burn at this point but nothing is visible.

The route meets a track and turns right at Duffenfoot, over a footbridge. Once across the Tipalt and climbing the winding walled track on the other side, it is possible to look back for a romantic view of the ruins of Thirlwall Castle. At the top of the track, with a line of trees on the left, the route crosses a stile by a gate and heads uphill beside a deep grassy ditch. This is the ditch excavated by the Romans on the north side of Hadrian’s Wall to hamper any attack by the Caledonian tribes. The wall itself has been dismantled; an ordinary drystone wall marks its course. At the top of the hill it is time to stop to orientate yourself by the views. If the air is fresh it should be possible to see Blenkinsopp Common and Cross Fell (the radio transmitting station on Great Dun Fell is distinctive; beside it is Little Dun Fell, then the more extensive low dome of Cross Fell at 2,930ft (893m). Looking eastwards, it should now be possible to see the dark grey cliff-face of the Great Whin Sill. Hadrian’s Wall follows the crest of this famous igneous intrusion for several miles, making the most of its daunting scarp slope. Beyond the field on the right, as the route continues eastwards, is the Museum of the Roman Army and the remains of one of Agricola’s forts, called Carvoran. This was built to protect the east–west road known as the Stanegate but was later employed as a garrison fort for the wall.

The route meets a road and turns right along this and then left into the Walltown Crags car park. Follow the surfaced path past the toilet block and disused quarry. What was once a dreadful eyesore, extracting dolerite for roadstone and slicing away a section of the Whin Sill and any Roman remains, is now a picnic site. Beyond the quarry, the path climbs to a kissing-gate. Go through this and bear left, uphill, to the crest of the Sill, to follow a particularly impressive section of Hadrian’s Wall. In places the remains of the wall stand at head height, but even here there is only a hint of how daunting the military barrier must have been, as when it was built the wall would have been three times taller. The rock is cut by deep gaps, created by meltwater at the end of the Ice Age, and the wall switchbacks and snakes along the best line of defence. The going is firm but never easy because of the undulating nature of the ridge. Jackdaws and wheatears nest among the columns of dolerite and among the sandstone boulders of the levelled turrets and milecastles.

At Great Chesters Farm, you’ll see the grass-covered ruins of the cavalry fort of Aesica.

The route drops down to a surfaced lane. Go right along this, over a bridge and then left. Turn right to enter the car park and little quarry picnic site at Cawfields. The Pennine Way then rises again for Cawfield Crags, where the wall is especially fine and the Vallum (the system of ridges and trenches which marked the Roman military zone) is easily visible to the south.

After Caw Gap, the Whin Sill rises to its highest point at 1,132ft (345m), with views west across the Solway to the Galloway hills. It then descends again to Steel Rigg, where there is a car park. A right turn along the road soon leads down to Once Brewed, where there is a visitor centre and youth hostel. Nearby is the Twice Brewed Inn, which has accommodation.