Scotland during the Roman Empire soon after 160. The destruction of some of the southern brochs may date to the Antonine advance, the hypothesis being that whether or not they had previously been symbols of Roman patronage they had now outlived their usefulness from a Roman point of view. The Roman frontier became Hadrian's Wall again, although Roman incursions into Scotland continued. Initially outpost forts were occupied in the south-west and Trimontium remained in use but they too were abandoned after the mid-180s. Roman troops, however, penetrated far into the north of modern Scotland several more times. Indeed, there is a greater density of Roman
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