Between the hills of the Taunus and the soft farmland of the Wetterau, the Roman frontier ran in a long, mostly straight line for most of the second and third centuries. This is Hesse, and the numbering that gives the place its odd label, watchtowers 4/36 and 4/37, refers to the standard system archaeologists use to count the Limes watchposts section by section. The point lies near Butzbach, a town of twenty-five thousand people where the frontier crossed the Wetterau and the local fort once held a cavalry unit. The section in question consists of the earth traces, a low bank and a ditch, that the Romans built in front of their wooden palisade, with towers spaced at regular intervals behind.
What you actually see is subtle. The Limes here has been worn down by farming and by time, and in many places it is a slight rise in a field or a line of trees that has grown on the old bank. In a few places signs or reconstructed towers explain the system. It helps to think of the frontier as a surveillance line rather than a defensive wall, for watchers on towers, a ditch to slow cattle thieves and a palisade to channel traffic toward gates where tax could be collected. The whole of it is part of the UNESCO Upper German-Raetian Limes.
The countryside is among the gentlest in Hesse, with fields of wheat and sugar beet, orchards, small streams and low hills, and the wind sweeps across the open Wetterau. Roads are well surfaced, with mild curves and some country lanes that run straight for a kilometre or two. The Taunus to the south offers more demanding bends, forest and view points, notably around the Feldberg. In summer, harvest machinery appears on the lanes, and in winter fog hangs on the plain. Spring and autumn are lovely.
Butzbach, about two kilometres away, has a market square lined with half-timbered houses, a museum with Roman objects and plenty of shops and cafés, with fuel on the roads around the town. Frankfurt is about forty kilometres to the south, and Giessen a similar distance north. Try a pork schnitzel with Frankfurt green sauce, and in the autumn the cider called Äppelwoi, if you are not riding. Observe the signs on field tracks, as farm lanes are often closed to motor traffic, and take care when passing tractors.