The remains of this once-formidable fort (known as Banna to the Romans) are on an escarpment overlooking the beautiful Irthing Gorge along a minor road off the B6318, 4 miles west of Greenhead in Cumbria. The longest intact stretch of wall extends from here to Harrow's Scar Milecastle. A 4m-high gatehouse leads to interactive, kid-friendly exhibits, which were revamped in 2018.
You can use bricks and a crane to work out how the wall was made, take a quiz to learn what role you might have played in the Roman army, and look through a periscope to see the same view that the Romans had from the wall's original height. There's a cafe and shop.