Near Butzbach the Wetterau starts to break against the Taunus, and the Roman frontier passes through that transition with a long series of numbered watchtowers, in this case 4/20 to 4/36. It is a longer run than most, and it reflects how carefully the Romans watched this side of the line, where the open plain makes a natural highway for anyone coming from the north. The Upper German-Raetian Limes, listed by UNESCO in 2005, crosses farmland here, and in places the old rampart survives as a low bank in a meadow edge or a stretch of forest.
Butzbach has a good Roman story on its own. A fort stood on the edge of the town, and the local museum and the nearby reconstructed bath complex tell you about life on the frontier, with bits of pottery, tombstones and tools. The medieval town is lovely, with a market square surrounded by half-timbered houses and a Gothic church, and Butzbach has about twenty-five thousand people, so it is the natural place to find fuel and a decent lunch. The nearby spa town of Bad Nauheim, a short ride south, is known for its Art Nouveau bathhouses.
The riding is excellent for an easy day. The landscape rolls with orchards, arable fields and small forests, and the B3 and its parallel back roads allow good progress, while the lanes towards Ober-Mörlen and Rockenberg offer calmer riding. The wind can be strong on open ground, and autumn fog sits in the hollows until mid-morning. If you want twisty roads, the Taunus is a short run to the south-west, and the ride up through beech forest to the Winterstein is the kind of climb that rewards patience.
At the stop itself you will not find much that rises above ankle height. Keep your expectations low, read the information board and imagine the gap in the trees that the Romans maintained on either side of the palisade. Then ask where the nearest cake is. In the Wetterau, a farm cafe is never far, and the local apple wine, Ebbelwoi, appears on menus in autumn. A short half hour is plenty, and an afternoon in the town is a better use of the day.