Architecture of Scotland in the Roman era England. Around 141 CE they moved up to construct a new "limes", a sward-covered wall made of turf known as the Antonine Wall, the largest Roman structure in modern Scotland. They soon retreated to Hadrian's Wall, with occasional expeditions that involved the building and reoccupation of forts, until the collapse of Roman power in the early fifth century. Caledonia was the name that the Romans gave to the land north of their province of Britannia. In his "Geographia", Ptolemy, possibly drawing on earlier sources of information as well as more contemporary accounts from the Agricolan invasion, identified 19 "towns" in
Scotland during the Roman Empire subjugating a population that did not conform to the strictures of local governance that Roman power usually depended on to operate through. The technology of everyday life is not well recorded, but archaeological evidence shows it to have been similar to that in Ireland and Anglo-Saxon England. Recently evidence has been found of watermills in Pictland and kilns were used for drying kernels of wheat or barley, not otherwise easy in the changeable, temperate climate. Although constructed in earlier times, brochs, roundhouses and crannogs remained in use into and beyond the Pictish period. Elsewhere in Scotland wheelhouses were constructed, probably