The Wetterau is a broad, fertile basin north of Frankfurt, one of the best farming landscapes in Hesse, and the Romans fenced it with a frontier that ran in a wide arc through the grain fields. This group of watchtowers, with its numbers running from 4/59 to 4/71, lies near Hungen and Lich on the eastern side, where the plain begins to rise toward the Vogelsberg. Close by stands the Eichkopf fortlet, and a few kilometres to the north the ruins of the big fort at Arnsburg lie beside the remains of a Cistercian abbey, a double dose of history under tall trees.
The roads are straightforward and enjoyable. Between the villages the Wetterau lanes run across open farmland in long curves, with big skies and the odd wind turbine. Further east the Vogelsberg rises, a vast extinct volcano and the largest basalt massif in central Europe, and its roads are gently winding and quiet, with forests and meadows and the occasional viewpoint. It is not a place for excitement, but the pace suits a relaxed day, and in late summer the cornfields glow and the hay smells sweet.
Lich is the town to know, with nearly fourteen thousand people and a good range of shops and cafes. It is also home to a well-known brewery, whose beer you will see on tap across the region. Hungen, a smaller town with just under five thousand people, has a castle, a few restaurants and a petrol station or two, so fuel is rarely a problem here. The abbey ruins at Arnsburg, in a wooded valley by the river Wetter, are a lovely quiet spot for a picnic, and they are free to wander.
Like the Limes elsewhere, the tower sites here are modest, a few earthworks, a stone marker or two, and a sign explaining what you cannot see. That is no reason to skip them, because they make the surrounding landscape feel inhabited. When you ride on, you may find yourself noticing the lines of hedges and the old field edges, wondering which of them follow a Roman instruction.