Rheinbrohl is where Germany's longest Roman frontier begins. The Upper Germanic Limes, a line of watchtowers, palisades and forts, starts at the Rhine here and runs east and south for some five hundred kilometres across Germany. At the Rheinbohl fortlet you can see the lines of a small Roman post, a few dozen soldiers who watched the river approach and the crossing over to the left bank. It is a modest place in terms of stonework, but the idea is wonderfully clear: an empire decided that this is where it ended, and put a post on the end of it.
The landscape is the Middle Rhine in its broad, northern form, where the valley is wide, the hills are low and the river is full of barges. Bad Hönningen, Rheinbrohl and Bad Breisig face each other across the water, and there are car ferries at several points. The vineyards start a little upstream, and the Westerwald rises behind the town in a long wooded wall. Spring is gentle, summer is hot and busy with cyclists, and autumn brings mist on the water and wine festivals in the villages.
The riding is a real treat if you pick it well. The federal road along the right bank is busy and uneventful, but the hills behind are full of quiet, curving roads that climb through woodland and drop through small villages. The corners are tight enough to be fun, the views open suddenly when the trees clear, and the surface is generally good, if worn by lorries in places. Watch for the railway line along the river and for speed cameras in the small towns, which are numerous and unforgiving.
Practicalities are easy. Bad Hönningen, a mile or two away, has fuel, a bakery, and cafes with views of the Rhine, and Bad Breisig and Neuwied offer more choice. The Römerwelt museum in Rheinbrohl explains the frontier, and the small town is pleasant for a stroll along the riverbank. Come in the late afternoon, when the river turns copper, and stay for a glass of local Riesling in one of the wine bars. It is a quiet beginning to a frontier that is, in the end, a very long line.