In 187 B.C. the Roman state, under the command of Marco Emilio Lepido, began the construction of the Via Aemilia, which connected Rimini to Piacenza.

Apart being an important way of communication, the Via Emilia soon became the main element around which urban, social, and economic projections of the region were organised.
Along this route, a series of urban centres and markets arose at regular intervals and today they still exist: Caesena (Cesena), Forum Livii (Forlì), Faventia (Faenza), Forum Cornelii (Imola), Bononia (Bologna), Mutina (Modena), Regium Lepidi (Reggio Emilia), Parma.
In the countryside, the road was usually made of gravel while, inside the towns, it was often paved with large stone slabs.

Imposing bridges crossed rivers and streams, such as the one near Castel San Pietro Terme, over the Gaiana Stream, destroyed during the Second World War.