The Wall does not end where most people think. Kirkland House is a name on the map; the point is the flat, open country around it, where the line of the Wall survives as a low, faint bank in places and a footpath on the line of the old ditch. The nearest listed towns, Annan and Eastriggs, are in Scotland across the water, so for a practical stop you want to look east and south instead, to Carlisle.
The Solway Firth is one of the great tidal estuaries of Britain, with a huge range between high and low water, and its salt marshes are a feeding ground for geese and waders in winter. Barnacle geese arrive in tens of thousands from Svalbard, and on a still October evening the sound is memorable. The tide can come in fast over the sands, so keep off the flats unless you know what you are doing. Nearby Burgh by Sands is the place where Edward I, the Hammer of the Scots, died in 1307 on his way north, and a monument stands on the marsh.
The riding is a quiet, slow business. The B5307 runs along the shore through villages with long views across the water to the Galloway hills, with the road flat and the corners gentle. A strong westerly can make it a fight, and the hedgerows funnel the wind. In summer the long light lasts for hours, and the sunsets across the firth are some of the best in the north. In winter, spray and flooding sometimes close the lower roads.
Fuel and shops are scarce on this coast, so fill up in Carlisle before heading out, or check the village shops, which may not open when you need them. The Hadrian's Wall Path ends at Bowness, and there is a pub, so you can have a pint beside walkers who have just completed the whole walk. Be ready to share the lanes with them, and with the odd tractor, and keep your speed low around blind bends.