Between Bowness-on-Solway and Drumburgh, the road follows the shore of the Solway Firth along a strip of land so flat and low that the highest tides cover it, and the line of Hadrian's Wall and its vallum runs just inland, through fields and past farms. This stretch, near Port Carlisle and Glasson, is part of the Frontiers of the Roman Empire World Heritage site. Little is visible of the Wall itself, which was robbed for stone long ago, but the vallum and other earthworks can be traced in places by those with a keen eye.
Port Carlisle has a curious history. In the early nineteenth century, a canal was built from Carlisle to the Solway here, with a basin and a harbour, to give the city access to the sea. It opened in 1823, but it was never a great success, and in the 1850s it was drained and converted into a railway, whose trains were later pulled by a horse in their final years. The remains of the canal basin and the harbour can still be seen, and the village is a peaceful place with a few houses and a pub.
Glasson Moss, inland from the shore, is one of the best-preserved lowland raised bogs in England, a national nature reserve with rare plants, insects and birds. The salt marshes along the shore are grazed by sheep and cattle and are home to thousands of waders and geese in winter. The views over the Solway to Scotland, with the hills of Dumfries and Galloway rising beyond, are beautiful, especially at sunset.
The riding here is gentle and peaceful, along narrow lanes beside the marshes, with little traffic. The road floods at high tides, with marker posts showing the depth, so check tide times and do not try to cross when the water is over the road. The landscape is flat and open, with huge skies and constantly changing light, and the wind can be strong.
Carlisle, about fifteen kilometres to the east, is the nearest city with all services. Wigton, to the south, is a small market town. Annan and Gretna, though close across the water, are a long way round by road. The pub in Port Carlisle and the one in Bowness are good stops for a pint and a meal.