Road station
A Dertona Iria
Tortona
Adertona Iria is not a place at all but a scrap of a written route: a Dertona Iria, from Dertona to Iria, that is, from Tortona to Voghera in northern Italy. It was copied from a list of stations to bridge the long gap between the two towns, but a later copyist no longer understood the little Latin word a, meaning from, and ran it into the name. The distance itself is missing from the map; the Roman register of routes gives ten Roman miles.