Antonine Wall wall was intended to extend Roman territory and dominance by replacing Hadrian's Wall to the south, as the frontier of "Britannia". But while the Romans did establish many forts and temporary camps further north of the Antonine Wall in order to protect their routes to the north of Scotland, they did not conquer the Caledonians, and the Antonine Wall suffered many attacks. The Romans called the land north of the wall "Caledonia", though in some contexts the term may refer to the whole area north of Hadrian's Wall. The Antonine Wall was shorter than Hadrian's Wall and built of turf
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