Imperial Roman army other military facilities e.g. Hadrian's Wall itself was built by the army. But they also built up much of a province's Roman infrastructure: trunk Roman roads, bridges, docks, canals, aqueducts, entire new cities such as "coloniae" for veteran legionaries, public buildings (e.g. basilicas and amphitheatres). The army also carried out large-scale projects to increase the land available for agriculture, such as forest clearance and draining marshes (e.g. the large-scale drainage of the Fens in eastern England, which were probably developed as a huge imperial estate). The army also excavated many of the mines and quarries that produced the raw materials
Newcastle town wall town wall was constructed during the 13th and 14th centuries to repel Scottish invaders. Newcastle is about from the River Tweed, which marks the border between England and Scotland, as it did then. At that time there was a power struggle between England and Scotland, that eventually led to the Wars of Scottish Independence. The Scottish kings were always ready to take advantage of any weakness in the English rule to invade the North of England. An example of this is David I of Scotland, who took advantage of the civil war between Stephen and Matilda to invade Northumberland in