History of Scotland 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, 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, which became the Antonine Wall. The largest Roman construction inside Scotland, it is a sward-covered wall made of turf around high, with nineteen forts. It extended for . Having taken twelve years to build, the wall was overrun and abandoned soon after 160. The Romans retreated to the line
Architecture of Scotland Trimontium, and a continuous fortification between the Firth of Forth and the Firth of Clyde known as the Antonine Wall, built in the second century AD. Beyond Roman influence, there is evidence of wheelhouses and underground souterrains. After the departure of the Romans there were a series of nucleated hill forts, often utilising major geographical features, as at Dunadd and Dunbarton. Castles arrived in Scotland with the introduction of feudalism in the twelfth century. Initially these were wooden motte-and-bailey constructions, but many were replaced by stone castles with a high curtain wall. In the late Middle Ages new castles were