Saint Patrick & Names along the Antonine wall

[MonsGraupius]

So this "hopelessly confused" person goes on to talk about Arthur's O'en, a Roman temple on the River Carron where there are "VII castellis munivit". However, you read this, there were seven fortified castles and the writer of the note is clearly referring to the Antonine wall.
Is your argument: "we should ignore any texts where we think there might be a mistake" - if so we may as well give up on Roman material.

Please accept my apologies; I thought I'd made my point clear.
It is quite obvious that we know more about the Antonine Wall than Nennius did:
It wasn't Septimius Severus who built the Antonine Wall. It isn't 132 miles long. It doesn't begin at Kinneil (if that is what the writer means by "the villa called in Scots Cenail but in English Peneltun"). It doesn't end at Kirkintilloch (which seems to be the "Cair Pentalloch" of the text).
And it doesn't have seven forts.

But we have now travelled far down a rabbit hole from the original discussion about the Ravenna Cosmography (which doesn't, in any case, name seven places across the isthmus)!

Is your argument that any text with, or suspected of being in error should be ignored? Because as you ought to know all Roman period texts have errors and if you took that attitude we'd discard almost everything we had and ... whilst we could be absolutely certain we didn't have any wrong information ... it would be because we had no information.

Or is your argument that this is a special case that deserves a specially difficult to pass test?

Because I don't think you dispute that the Antonine wall is clearly being referred to, nor have you disputed that there were seven castles. If you don't dispute these - then what then is your argument?

To answer specific points - We don't know how long it was at the time of the note. We do know that today the vast bulk of any visible remains of the Roman wall are between Barhill and Kinneil. Barhill is just east of Kirkintilloch - so if the writer were talking about the wall at their time (and remember it was built of turf) you cannot say they were wrong.

It doesn't say "built" but "rebuilt" - and Roman texts are lacking at the time of emperor Carausius so again it is very difficult to say "we know they are wrong". Thus there is only one substantial error, which is the length.

However, as far as I can tell, you do not dispute it was talking about the Antonine wall, nor do you dispute that it says Seven castles.