Scotland in the Early Middle Ages to be adopted for house building, often combining layers of stone with turf. Place-name evidence, particularly the use of the prefix "pit", meaning land or a field, suggests that the heaviest areas of Pictish settlement were in modern Fife, Perthshire, Angus, Aberdeen and around the Moray Firth, although later Gaelic migration may have erased some Pictish names from the record. Early Gaelic settlement appears to have been in the regions of the western mainland of Scotland between Cowal and Ardnamurchan, and the adjacent islands, later extending up the West coast in the 8th century. There is place name and archaeological
Architecture of Scotland a line drawn between the Tyne and Solway Firth. Elginhaugh fort, in Midlothian, dates to about this period as may Castle Greg in West Lothian. The Romans eventually withdrew to a line in what is now northern England, building the fortification known as Hadrian's Wall from coast to coast. Around 141 A.D. the Romans undertook a reoccupation of southern Scotland, moving up to construct a new "limes" between the Firth of Forth and the Firth of Clyde. The Antonine Wall is the largest Roman construction inside Scotland. It is a sward-covered wall made of turf circa 7 metres (20 ft)