Hadrian's Wall is a remarkable feat of engineering, architecture, and military strategy that has stood the test of time for over two millennia. Built by the Roman Empire in 120 AD, the wall stretches for 73 miles across northern England, from the River Tyne in the east to the Solway Firth in the west. It was constructed during the reign of Emperor Hadrian, who ordered its construction as a defensive barrier against the barbarian tribes of Scotland.