For a stretch of about fifty kilometres, the Roman frontier of Upper Germany did not need a wall at all. Between Großkrotzenburg and Miltenberg, the Main river itself served as the border, and the Romans lined its western bank with forts and watchtowers to watch over the water and the forested hills of the Spessart on the other side. Wörth am Main had one of these forts, with a civil settlement where soldiers' families, traders and craftsmen lived. Very little remains above ground, but this wet frontier is inscribed as part of the Upper German Limes, and standing on the riverbank you can see why the Romans thought the river was enough.
Wörth is a small, attractive town of about five thousand people, with half-timbered houses and a riverside promenade. It has a museum of shipping and shipbuilding, a reminder that the Main has long been a busy waterway, with barges carrying sand, stone and timber. The red sandstone of the region, quarried along the river, was used to build much of the town, as well as churches and castles far and wide.
Across the river and up the valley, Klingenberg is known for its red wines grown on steep terraces above the town, some of the best Spätburgunder in Franconia, and Miltenberg, a little further upstream, is one of the most beautiful small towns in Germany, with a market square of half-timbered houses and a castle above. Erlenbach am Main, right next door, is the nearest larger town, with fuel and shops.
The riding here is excellent. The Main valley road follows the river through vineyards, forests and towns, with gentle curves and lovely views, though it can be busy at weekends. On either side, the Spessart and the Odenwald offer some of the best riding in central Germany: quiet roads through dense forests, climbing and descending through small villages, with plenty of curves. Watch for cyclists, deer at dusk and speed cameras. In autumn, when the forests turn gold and the grape harvest is in full swing, the region is at its most beautiful. Try Franconian wine served in its traditional round bottle, the Bocksbeutel, and local sausages and roasts in a riverside inn.