The Taunus ridge rises north of Frankfurt like a long, forested wall, and the Romans did not try to cross it. Their frontier line swung around its northern slopes, through the Wetterau, and then down toward the Main, and this section lies near Langgöns, close to the valley of the Lahn and a short ride from Giessen. The five towers of the stretch numbered 4/40 to 4/44 followed the ridge lines in a sequence that let each one see the next, and a signal tower on the Johannisberg, a modest hill, linked them. Of all these only footings and mounds remain, but the surveying logic is easy to read once you stand on high ground and look toward the next rise.
Roman soldiers who served here came from many provinces. Auxiliary units drawn from places as distant as Spain, Syria and Thrace were posted along the Limes, and their gravestones, found in local museums, give names and ranks in Latin. The line was abandoned in the middle of the third century, and the local people took the stone for their own buildings, so that a medieval church wall may contain a block from a Roman tower. The Upper German-Raetian Limes is now a UNESCO World Heritage Site.
The country here is a mix of orchards, small woods and low hills, among them the foothills of the Taunus and the Vogelsberg, and the roads between the villages are well surfaced, with moderate curves, short climbs and patches of woodland shade. Lanes sometimes narrow to a single track, and farm vehicles appear without warning. In spring the blossom is thick on the apple trees, and in autumn the woods are mellow. Winter mornings can bring black ice on shaded stretches, and in summer thunderstorms break suddenly in the afternoons.
Langgöns, three kilometres away, has about twelve thousand people, fuel stations, shops and several bakeries and restaurants, and the university town of Giessen, a short ride to the north, offers more. Try a plate of local Hessian dishes, such as grüne Soße, a green herb sauce eaten with potatoes and eggs, or a cup of coffee and a slice of Zwetschgenkuchen, plum cake, in season. Many of the paths to the tower sites are forest tracks closed to motor vehicles, so leave the bike at a car park and walk, and carry a map, since mobile signals are patchy under the trees.