I learned of this via Michael Portillo on Great Coastal Railway Journeys. We must go.
And, to my great annoyance, I’ve just realised that we missed a Topping Books talk, Monday evening, on the Roman Army: Legion, by Richard Adby.
Called Gariannonum, it’s thought to have possibly been a cavalry fort. And it’s one of the best preserved Roman remains in the UK. Another destination for our future travels.