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 to purchase truces from the natives, and eventually the spread of Christianity. The Ravenna Cosmography utilises a 3rd- or 4th-century Roman map and identifies four "loci" (meeting places, possibly markets) in southern Scotland. "Locus Maponi" is possibly the modern Lochmabenstane near Gretna which continued to be used as a muster point well into the historic period. Two of the others indicate meeting places of the Damnonii and Selgovae, and the fourth, "Manavi" may be Clackmannan. From the time of Caracalla onwards, no further attempts were made to permanently occupy territory in Scotland. The intermittent Roman presence in Scotland coincided with