Analysis of the orientation of the Decumanus of Roman Dertona

This work proposes a study of the planning of the Roman Dertona, today Tortona, in Piemonte, according to three possibilities. We will see its layout in function of the natural environment which is surrounding it (secundum naturam), of the roman roads which were passing thorough the area, and according to a possible astronomical orientation (secundum coelum). This last analysis will allow us to define a possible year for the foundation of the town.