Hadrian's Wall (at Milecastle 39)

Map of Hadrians Wall

Hadrian's Wall (Latin: Vallum Aelium, "Aelian Wall" – the Latin name is inferred from text on the Staffordshire Moorlands Patera) was a defensive fortification in Roman Britain. Begun in AD 122, during the rule of emperor Hadrian, it was the first of two fortifications built across Great Britain, the second being the Antonine Wall, lesser known of the two because its physical remains are less evident today.

• http://en.wikipedia.org/wiki/Hadrian's Wall