It may have also been torched by the workers before they fled to prevent it from falling into Roman hands.
It's my belief, iron and ironstone being high value, they'd have taken what they could with them, the inputs. Charcoal aside, the remains otherwise are more marginal value, you can do Iron in a mud brick hearth, there wouldn't have been a lot of immovable fixed infrastructure to take really. The charcoal is a pain to make, time consuming. Maybe they burned that to avoid the romans having access, but I tend to think t…
This is so true. If you ask for help, people will ignore you. But... if you post the wrong answer--people will fall over themselves to correct you. It's like a hack for human behavior.