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
Planetrees (Hadrian's Wall section) he must have a mean opinion of me, who would travel six hundred miles to see it; and if it was, he could never merit my thanks for destroying it." The eastern part of the surviving section (approximately in length) is built as Broad Wall, 10 Roman Feet wide. The eastern section (approximately in length is built as Narrow Wall, 8 Roman Feet wide, yet still on foundations clearly installed for a Broad Wall. The join is archeologically interesting, as it suggests a change in plan during construction. Also present on the narrow wall stretch is a culvert. The stones