Hadrian's Wall

Hadrian's Wall is a stone and turf fortification built by the Roman Empire across the width of modern-day England. It was the second of three such fortifications built across Great Britain, the first being Gask Ridge and the last the Antonine Wall. All three were built to prevent military raids by the Pictish tribes (ancient inhabitants of Scotland) to the north, to improve economic stability and provide peaceful conditions in the Roman province of Britannia to the south, and to mark physically the frontier of the Empire. Hadrian's Wall is the best known of the three because its physical presence remains most evident today.
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Noun
1. an ancient Roman wall built by Hadrian in the 2nd century; marked the northern boundary of the Roman Empire in Britain
(hypernym) wall
(part-holonym) England