Initially established in late 2006 to host what was probably the first publicly available digital mapping exercise for Hadrian’s Wall, Per Lineam Valli uses that original data to present a new encyclopaedic atlas of the Roman frontier in the north of England (which, it should be noted, was never the border between England and Scotland, even when those entities finally came into existence). At the same time, some of the older examples of mapping of the Wall from the 18th, 19th, and 20th centuries are presented here for some context.
The Romans recorded Hadrian’s Wall as being 80 Roman miles long (Historia Augusta, Hadrian 11.2). The length of a Roman mile varied according to mood, region, and accuracy of recording, but acceptable approximations would be 118.5km, 129,600yd, 388,800ft, or 73.64 statute miles.
Accompanying this website, there is also a Per Lineam Valli blog and Twitter account, where you should expect most of the activity (and news of updates to this website) to be found.