Hadrian's Wall

(known in antiquity as the Vallum Hadriani or the Vallum Aelian) is a defensive frontier work in northern Britain which dates from 122 CE. The wall ran from coast to coast at a length of 73 statute miles (120 km). Though the wall is commonly thought to have been built to mark the boundary line between Britain and Scotland, this is not so; no one knows the actual motivation behind its construction but it does not delineate a boundary between two countries.