The walk starts from the highest point on the cross-border drove road called Clennell Street. This can be reached from the nearest road at Cocklawfoot, which is 2.2 miles (3.5km) to the northeast, or from the nearest village, Alwinton, which is 7.6 miles (12.2km) to the south. An area that is often shrouded in mist, route-finding is made easier by the almost constant presence of a fence. The route first follows the border fence along a broad ridge – Butt Roads – crossed via flagstones. It then rises to King’s Seat, where there is nothing but a triangulation point and wide acres of windswept heather. The ridge on the English side drops away to Usway Burn (pronounced Oozy or Uzzy). Several small streams drain the ridge eastwards, including Murder Cleugh and the Inner Hare Cleugh, where Black Rory the Highlander established one of his illicit stills 200 years ago.

Above King’s Seat there is a long pull northeastwards, by Green Gair and Cockersike Head, and although the ground is boggy the route is mainly by stone flagged path. As the route climbs even more steeply towards Cairn Hill there is a tumble of rocks on the brow to the right called the Hanging Stone; another place of ill-repute which marked the boundary between the Middle and East Marches.

The main route of the Pennine Way stops short of the peaty top of Cairn Hill, although those who decide to follow the optional detour on to The Cheviot (see ‘While You’re There’ ) will pass it. The main route heads sharp left, at a stile and over flagstones across very wet ground to Auchope. There is then a descent, past another wooden refuge hut, at a strategic place where conditions can be treacherous and there is no easy escape route. In good light the views are excellent; over your right shoulder is the Hen Hole, a hanging valley by which the College Burn leaps and rushes down through the andesite and heads north to join the River Glen at Kirknewton. The hills are the haunt of wild goats and peregrines.

The next summit is the Schil, a shapely top, and one of the most beautiful links along the whole chain of border hills. The views are breathtaking, as is the climb. On its northern side there are several rocky tors; tors of baked andesite are small but important features of the inner Cheviots. An exhilarating descent along the border fence from the Schil leads to a dip.

The Pennine Way crosses into Scotland via a ladder stile near the base of Black Hag. It briefly veers away from the border fence to reach a fingerpost. There are two options here: the low-level alternative goes left, reaching Kirk Yetholm in 4 miles, while the main route heads right (4.5 miles to Kirk Yetholm). Opting for the higher version to the right, there is one more memorable stretch, as the path rises to Steerig Knowe and then sweeps along the crest of Steer Rig, with the basin of the Trowhope Burn to the right and the twin-peaked summit of Coldsmouth Hill ahead. The top of White Law is magnificent, offering the last panorama, across to the Tweed and to Flodden where the Scots were finally defeated in 1513, and into the Cheviot foothills.