Between the Lahn and the Rhine, the Roman frontier crossed a high, wooded plateau known locally as the Einrich, and the watchtowers from 2/7 to 2/13 stood on this stretch, near the village of Dachsenhausen. In the forest, the earth bank and ditch can still be followed, and small forts, built to house the soldiers who manned the towers, have left their outlines in the ground. Here, as elsewhere in Germany, the Limes belongs to the frontiers of the Roman Empire on the World Heritage list, but the forest is quiet, and you may walk the line for an hour without meeting anyone.
Below the plateau, the Lahn winds through a deep, wooded valley, and the little town of Nassau sits on its banks, overlooked by the castle that gave its name to one of Europe's great dynasties. The counts of Nassau built it in the twelfth century, and their descendants went on to rule in the Netherlands, where the royal house of Orange-Nassau still bears the name. Nassau was also the birthplace of Karl vom Stein, the Prussian statesman who reformed the state in the early nineteenth century; his family's town house stands in the centre.
Upstream, Bad Ems is an elegant spa town, where emperors and kings once came to take the waters, and where in 1870 the Ems Dispatch, a telegram edited by Bismarck, provoked the Franco-Prussian War. Bad Ems is part of the Great Spa Towns of Europe on the World Heritage list. Dausenau, between Bad Ems and Nassau, has a leaning medieval tower and an old inn.
The riding is varied and excellent. The Lahn valley road follows the river through forests and past castles, with gentle curves and lovely views, while the Bäderstraße, the B260, climbs from Bad Ems over the Taunus towards Wiesbaden, a road popular with riders for its curves and scenery. Smaller roads on the plateau link quiet villages through farmland and forest. Watch for cyclists, campervans on the Lahn and deer at dusk. Nassau, with about five thousand people, has fuel and shops; Bad Ems has more choice. The Lahn is popular for canoeing in summer, and a riverside beer garden is a fine place for a break.