The iconic wall constructed during the Roman Empire that marked the northern limit of Roman Britain is Hadrian's Wall. Built under Emperor Hadrian starting in AD 122, this fortification stretched across northern England and served multiple purposes: defense, border control, and troop movement. The wall is emblematic of Roman engineering and military strategy and features forts, turrets, and settlements along its length. Although much of it is now in ruins, it remains a UNESCO World Heritage Site and an important archaeological landmark representing Roman Britain.