Kastell Holzhausen is one of the best-preserved Roman forts along the German Limes, and it lies in a forest clearing near the village of Holzhausen an der Haide in the western Taunus, where the remains of its stone walls, gates and corner towers still stand to a height of a metre or more. The fort housed an auxiliary cohort of several hundred soldiers in the second and third centuries, and it guarded a section of the frontier, the Upper Germanic-Raetian Limes, along with a chain of watchtowers spaced at regular intervals along the line. The watchtowers numbered WP 2/26 to 2/30, part of the UNESCO listing, stood on this section between the fort and its neighbours.
The watchtowers were the eyes of the frontier. Built first of wood and later of stone, they stood a few hundred metres apart, within sight of each other, so that signals could be passed along the line. Soldiers stationed in them watched the palisade and the land beyond, and could call for help from the forts if trouble appeared. Most of the towers survive only as low mounds in the forest, but walking the Limes trail, you can still trace the line of the frontier, with the bank and ditch visible among the trees.
The western Taunus is a quiet, rolling landscape of forests and fields, with small villages and farms, between the Rhine, the Lahn and the Aar. The roads are narrow and winding, with generally good surfaces and light traffic, and they offer relaxed riding through the forest and over the hills. The B260, the Bäderstraße, runs from Wiesbaden north-west through the Taunus to Bad Ems and the Lahn valley, a scenic route through forests and villages, popular with riders.
Nearby, the Aar valley, with the towns of Hohenstein and Michelbach, has winding roads and castle ruins, and to the west, the Rhine gorge, with its castles and vineyards, is a short ride away.
Nastätten, about five kilometres away, has fuel and basic services; Nassau, about eleven kilometres away, is larger. In the villages, look for a country inn, a Landgasthof, serving local dishes like Sauerbraten, marinated pot roast with red cabbage and potato dumplings, or schnitzel with mushroom sauce. And take the time to walk around the walls of the fort, imagining the soldiers who once lived here, on the edge of the empire, far from home.