Hispellum - Imago urbis. Considerazioni su Porta Venere e sulle altre porte urbiche della cinta romana di Spello

The striking city walls of Spello have ensured that the forma urbis of this Roman colony has remained unchanged over time. The fortification, which dates back to the early imperial period and has largely been preserved to this day, has seen a number of different attempts to interpret and hypothetically reconstruct its gateways since the sixteenth century. The first of these was Sebastiano Serlio who included the monumental Porta Venere entrance in his Third Book of Architecture. Following a specific historical investigation into Roman facies in the city and surrounding area, which cross- referenced ancient sources with local archaeological documents, this text proposed an analysis of the main entrances to the walled city by direct surveying. The unique character of the entire fortified structure was brought to light through comparison of the entrances among themselves and with similar fortified structures and city gateways in Umbria and Italy of more or less the same age. Thanks to a metrological analysis of the transposition of metric measurements into Roman feet, the conclusion was that the Venere gateway was “sacred” in nature, justified by the presence of the extra- urban temple located opposite.