Hadrian's Wall stopped at Bowness-on-Solway, but the Roman frontier did not. Down the Cumbrian coast, the army built a chain of forts, milefortlets and towers to watch the sea and stop raiders slipping round the end of the Wall, and Parton, just north of Whitehaven, was one of them. The fort is known from excavations and records rather than standing remains, and the coastal defences as a whole are included in the UNESCO Frontiers of the Roman Empire. Standing on the cliffs above the sea, you can see why the Romans worried: across the water lie the Isle of Man and, on clear days, the hills of Scotland.
Whitehaven, next door, is a fascinating town in its own right. In the seventeenth and eighteenth centuries it was one of the busiest ports in Britain, grown rich on coal, tobacco, rum and, uncomfortably, the slave trade. Its Georgian streets were laid out on a grid, one of the first planned towns in post-medieval England, and the harbour is still the heart of the place. In 1778 the American naval commander John Paul Jones raided the harbour, an episode the town remembers with some pride.
The riding on the Cumbrian coast is a mix of fast main road and quieter lanes. The A595 runs along the coast, busy with trucks and commuters, while minor roads head inland into the western fells of the Lake District, toward Ennerdale and Loweswater, with narrow, twisting lanes and wonderful views. Weather here comes straight off the Irish Sea, with wind and rain common, and the light can change dramatically within minutes.
Whitehaven has fuel, shops, cafés and pubs, and the harbour area is a pleasant place to eat. The Beacon Museum tells the story of the town, its mines and its maritime trade. The coast to coast cycle route begins here, so expect cyclists dipping their wheels in the harbour. Local food includes fish, Cumberland sausage and sticky toffee pudding, a dish born in Cumbria.
Visit on a clear day if you can, when the views across the sea are long and the evening light turns the water gold. Then walk the cliff path north of the harbour for half an hour, with fulmars wheeling below and the wind in your face, and finish with fish and chips on the quay.