The Roman frontier wall known as the Limes ran for more than five hundred kilometres across what is now southern Germany, from the Rhine to the Danube, and near Aalen it passed through the Kocher valley and over the hills of the Ostalb. Along its length, watchtowers were built at regular intervals, numbered by archaeologists in sequence: WP 12/60 to 12/68 are a group of tower sites near Hüttlingen, mostly now visible as low mounds or reconstructed foundations. The Upper Germanic-Raetian Limes was inscribed by UNESCO in 2005 as part of the Frontiers of the Roman Empire.
Aalen, a few kilometres away, was home to the largest Roman cavalry fort north of the Alps, garrisoned by a unit of a thousand horsemen, and the Limesmuseum there displays the finds and tells the story of life on the frontier, with reconstructions and a park on the site of the fort. The Kocher river flows through the valley, and the Ostalb, the eastern part of the Swabian Jura, rises around, a landscape of forested hills, juniper heaths and limestone cliffs.
The roads here are a pleasure: quiet, well surfaced, with gentle curves through the valleys and over the hills. The Deutsche Limesstraße, a signposted touring route, follows the line of the frontier through the region, and the roads of the Ostalb, through forests and villages, offer good riding. Traffic is light except near the towns, and the scenery is varied and attractive. The Ostalb is at its best in early summer, when the juniper heaths are in flower and the evenings stay light until late.
Hüttlingen, just down the Kocher valley, can fill the tank, and Aalen, a town of nearly seventy thousand people, covers everything else. The Limesmuseum deserves a couple of hours, with its full-size reconstructions, cavalry equipment and the outline of the vast fort laid out in the park. Swabian inns in the area serve Zwiebelrostbraten, roast beef under a heap of fried onions, with Spätzle on the side, and the local beers from small breweries in the Ostalb are excellent. Aalen's old town, compact and pleasant, makes a good evening stroll after a day on the road.