After abandoning the Alblimes (a Limes generally following the ridgeline of the Swabian Jura) around 150 AD, Aalen's territory became part of the Roman Empire, in direct vicinity of the then newly erected Rhaetian Limes. The Romans erected a castrum to house the cavalry unit Ala II Flavia milliaria; its remains are known today as Kastell Aalen. The site is west of today's town centre at the bottom of the Schillerhöhe hill. With about 1,000 horsemen and nearly as many grooms, it was the greatest fort of auxiliaries along the Rhaetian Limes. There were Civilian settlements adjacent along the south and the east. Around 260 AD, the Romans gave up the fort as they withdrew their presence in unoccupied Germania back to the Rhine and Danube rivers, and the Alamanni took over the region. Based on 3rd- and 4th-century coins found, the civilian settlement continued to exist for the time being. However, there is no evidence of continued civilization between the Roman era and the Middle Ages.
There is a Limes Museum located adjacent the Kastell.
References:The Château du Lude is one of the many great châteaux of the Loire Valley in France. Le Lude is the most northerly château of the Loire Valley and one of the last important historic castles in France, still inhabited by the same family for the last 260 years. The château is testimony to four centuries of French architecture, as a stronghold transformed into an elegant house during the Renaissance and the 18th century. The monument is located in the valley of Le Loir. Its gardens have evolved throughout the centuries.