Banna, now known as Birdoswald Roman Fort, was a fort, towards the western end of Hadrian's Wall, in the Roman province of Britannia. Today the site is occupied by a former farm called Birdoswald. As of 2005, it is the only site on Hadrian's Wall at which significant occupation in the post-Roman period has been proven, and it is subject to a long-term archaeological programme under the directorship of Tony Wilmott.