The late-antiquity crisis caused the disappearance of several cities in Italy, for the Regio VIII this situation is evident if we compare the Pliny’s list of the cities in Aemilia (I d.C.) to the of the early-medieval dioceses: 12/24 cities disappeared. Tannetum is one of these, it is generally identified with Sant’Ilario d’Enza because the ancient itinerary inform us that it was on the via Aemilia, between Parma and Regium Lepidi, as this small town is. Archaeology anyway shows a lack of roman remains in the town and almost all consists in tombs. On the contrary 1 km north, there is the small village of Taneto that keeps memory in its name of the lost roman city. In this paper we present new data that seem to indicate that the lost city was near to Taneto, in particular some aerial photos reveal traces of ancient buildings underground, maybe also an amphitheatre. Also the roman land division is here very problematic, it should be part of the adsignatio viritim of 173 a. C. but near to the Enza river there is a regular land division totally differently orientated from the other territories, in this paper we suggest a possible explanation to this anomalous pattern.