The famous wall that the Romans built in Britain is Hadrian's Wall. Constructed under the Roman Emperor Hadrian starting in AD 122, the wall stretched approximately 73 miles across the north of England, providing a defensive frontier against the tribes in what is now Scotland. Built from stone and turf, Hadrian's Wall included fortifications such as forts, watch towers, and settlements. Its purpose was both military and administrative, controlling trade and immigration. Today, it is a UNESCO World Heritage Site, attracting tourists and historians who are interested in Roman history and the impact of Roman rule in Britain.