West of Haltwhistle, the land rises gently to the watershed between the Tyne and the Irthing, a broad, windy saddle of rough pasture known as the Tyne Gap, where rivers flow east to the North Sea and west to the Irish Sea. Chapel Rigg Roman temporary camp is one of several marching camps here, where Roman soldiers on the move dug a rectangular ditch and rampart for a night or a season, the earthworks now barely visible as low ridges in the grass. It is part of the Frontiers of the Roman Empire World Heritage site.
The camps make sense once you see the lie of the land. This gap is the easiest route across northern England, and the Romans used it for the Stanegate road, and later the Wall, both of which run nearby. Close by is Walltown Crags, where the Wall climbs along the top of a dramatic line of cliffs formed by the Whin Sill, a band of hard volcanic rock that runs across Northumberland. At Carvoran, below Walltown, the Roman Army Museum tells the story of the soldiers who served on the Wall, with reconstructions, films and artefacts.
Thirlwall Castle, a ruined medieval tower house built partly from Roman stones, stands above the Tipalt Burn near Greenhead, a reminder of the violent centuries when the Border Reivers raided back and forth across this land. Its name comes from the gap in the Wall through which raiders passed, the thirled or holed wall.
The riding here is excellent. The Military Road, B6318, runs along the line of the Wall from Greenhead eastwards, with long straights, steep dips and blind crests, and views over the crags and loughs. The A69 is faster but less interesting. Minor roads into the moors to the north and the South Tyne valley to the south are quiet and twisty. Beware of sheep, walkers and changeable weather.
Haltwhistle, about six kilometres away, has fuel, shops and cafés. Greenhead, a small village nearby, has a tea room and a pub. Brampton and Hexham are larger towns with more options. The Roman Army Museum at Carvoran has a café, and the view from Walltown Crags at sunset is worth the short walk from the car park.