Here the Wall is at its most dramatic. In the central sector of Hadrian's Wall, north of Haydon Bridge and Hexham in Northumberland, the Roman frontier runs along the top of the Whin Sill, a long ridge of hard volcanic rock that breaks the moorland into a series of north-facing cliffs. The Romans built their wall right along the crest, using the natural defences, and the result is a line of stone that rises and falls with the crags like the spine of a great animal. Behind it, to the south, runs the vallum, a broad earthwork ditch with mounds on either side that marked the military zone, still clearly visible across the fields.
The Wall was begun in the early 120s on the orders of the emperor Hadrian, running from coast to coast for about seventy-three miles, with forts, milecastles and turrets along its length. Housesteads fort, a short distance west, is the best-preserved of them all, and Vindolanda, to the south-west, has yielded the famous writing tablets, letters and notes that bring the soldiers and their families vividly to life. To the east lies Carrawburgh, with a small temple to the god Mithras standing in a boggy field.
The main road through the area, the B6318, is known as the Military Road. It was built in the eighteenth century by General Wade's successors after the Jacobite rising of 1745, and for long stretches it was laid right on top of the Roman wall, using its stones. It runs straight across the moors with steep dips and blind crests that can launch a careless rider, so take care. The views are wide and wonderful, the traffic usually light, though tourist coaches are common in summer.
Weather here can change in an instant. A sunny morning can bring sideways rain by noon, and fog sometimes rolls over the crags, so pack waterproofs and warm layers in every season. Sheep wander freely on the road, and the surface can be greasy with mud near farm entrances.
Hexham, about thirteen kilometres away, is the market town for fuel, shops and food, with a fine abbey to visit as well. Pubs and cafés near the Wall offer hearty meals and a warm fire.