Architecture of Scotland in the Roman era 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 CE 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 resulting Antonine Wall is the largest Roman construction inside Scotland. It is a sward-covered wall made of turf, around high, with nineteen forts and extending for . The stone foundations and
Scotland during the Roman Empire fortification built across the width of what is now northern England. The wall was 80 Roman miles (73.5 statute miles or 117 kilometres) long, its width and height dependent on the construction materials which were available nearby. East of the River Irthing the wall was made from squared stone and measured 3 metres (9.7 ft) wide and 5–6 metres (16–20 ft) high, while west of the river the wall was originally made from turf and measured 6 metres (20 ft) wide and 3.5 metres (11.5 ft) high; it was subsequently rebuilt in stone. The wall was augmented by various ditches,