Cornovii (Cornwall) Dumnoniorum (present day Exeter), it is likely that he only listed Roman places, not purely native sites. Of these, there has been speculation that Voliba might be a place in Cornwall and Tamara is assumed to be on the River Tamar, the border between Cornwall and Devon. Ptolemy's list is supplemented by the problematical Ravenna Cosmography, which lists sixteen names before Isca Dumnoniorum (which is listed as "scadum namorum", showing some of the problems of this source) and which have therefore been assumed to be west of Exeter. Several have been identified as most likely in Devon, leaving "purocoronavis" (the
Isca Augusta the Silures in South Wales who had resisted the Romans’ advance for over a generation. Isca became the headquarters of the Legion II Augusta based in the large fortress of typical legionary "playing-card" shape and built initially with an earth bank and timber palisade. It remained their headquarters until at least 300 AD. The interior was fitted out with the usual array of military buildings: a headquarters building, legate's residence, tribunes' houses, hospital, large bath house, workshops, barrack blocks, granaries and, unusually, a large amphitheatre.. At this time there were 4 legions in Britain out of a total of about