The Raetian Limes, the eastern stretch of Rome's frontier in Germany, was built differently from its western counterpart. Instead of a wooden palisade, the Romans eventually raised a stone wall here, running for over a hundred and sixty kilometres across what is now Bavaria, towards the Danube. Locals later called it the Teufelsmauer, the Devil's Wall, convinced that only a demon could have built something so long. Watchtowers stood along it every few hundred metres, and the group between WP 15/8 and 15/10, in the hills between Greding and Dietfurt, is part of the UNESCO World Heritage site of the Frontiers of the Roman Empire. In places, low remains of the wall and towers can be traced in the forest and fields.
The area lies within the Altmühltal Nature Park, one of Germany's largest nature parks, a landscape of limestone plateaus cut by deep valleys, with juniper heaths, rocky cliffs and quiet villages. The Altmühl river winds slowly through it, and at Solnhofen, to the west, quarries of fine limestone have yielded the famous Archaeopteryx fossils, the feathered link between dinosaurs and birds. The limestone was also used for lithography printing stones around the world.
To the south-east, at Kelheim, the Danube cuts through a narrow gorge, and Weltenburg Abbey, on a bend of the river, has a Baroque church and one of the oldest monastic breweries in the world. Greding has an almost complete medieval town wall with towers, and Dietfurt holds a famous Chinese-themed carnival every year, a local tradition with a curious history.
The riding is excellent. Roads wind through valleys and over plateaus, with plenty of bends, gentle climbs and little traffic away from the main routes. Surfaces are generally good. Watch for cyclists, especially along the Altmühl, and tractors in the fields. Wildlife crosses frequently, and fog can fill the valleys in the mornings in autumn. Summer weekends bring more traffic and police checks.
Greding, about fourteen kilometres away, has fuel, shops and inns. Try a Bavarian lunch, roast pork with dumplings, or a plate of local trout, with a beer from one of the many small breweries in the region, saving the beer for when the bike is parked for the night.