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.
