aerial photograph of Birdoswald Roman Fort on Hadrian's Wall Cumbria England UK

aerial photograph of Birdoswald Roman Fort on Hadrian's Wall , England. The Romans built 16 forts, about one every 5 miles mile along the length of Hadrian's Wall with additional small mile castles built every mile . Built between 122 AD and 128 AD the wall was used up until the Romans left Britain in 410 AD. Birdoswald was known to the Romans as Banna and recent archaeological excavations have shown it was in use for 100 years after the Romans left Britain.