Architecture of Scotland in the Roman era which were later replaced by forts. The most visible fortlet is Kinneil, at the eastern end of the Wall, near Bo'ness. Having taken twelve years to build, the wall was overrun and abandoned soon after CE 160. The Romans retreated to the line of Hadrian's Wall. Roman troops penetrated far into the north of modern Scotland several more times, with at least four major campaigns. The Antonine Wall was occupied again for a brief period after 197 CE. The most notable invasion was in 209 when the emperor Septimius Severus led a major campaign. A string of forts was constructed
Architecture of Scotland in the Roman era in the north-east (some of which may have been begun in the earlier Antonine campaign). These include camps associated with the Elsick Mounth, such as Normandykes, Ythan Wells, Deers Den and Glenmailen. However, only two forts in Scotland, at Cramond and Carpow (in the Tay valley) are definitely known to have been permanently occupied during this incursion. There is evidence that these campaigns are coincident with the wholesale destruction and abandonment of souterrains in southern Scotland. This may have been due either to Roman military aggression or the collapse of local grain markets in the wake of Roman withdrawal. After