Just when everybody has been telling you Hadrian's Wall is 80 Roman miles long, you discover that in fact it was 81! Due to an accounting error (or perhaps somebody simply got out of bed on the wrong side one wall-numbering day), the first Wall Mile is Wall Mile 0, not Wall Mile 1 as you might expect. To be fair, nobody has ever actually found MC1 or even MC0, nor are they completely sure where they might be, since it all depends where the start is measured from. Of course, this is (all too literally) a measure of our lack of understanding of the problem, rather than any obfuscation on the part of the Romans who, so far as we know, never even bothered numbering it.
If we continue eastwards along Fossway it eventually turns into Maurice Road and then, striking north-eastwards, becomes Neptune Road and then Buddle Street. At this point, the Segedunum museum at Wallsend fort becomes evident to our right and, to our left, a reconstructed length of the curtain wall.Via http://perlineamvalli.wordpress.com/2012/05/29/wall-mile-0/