Porta Nuova (Porta Volterrana)The gate on the Volterra road was built on the site of the Porta Selva, which was destroyed by troops allied to the Siennese during the siege of 1479. At the time, the bastions and the battlements were already present, while the gateway as it appears today, giving access to the Borgo di Santa Caterina, was built together with the new outer walls by the Florentine architects Cecca, Francione and Giuliano da San Gallo.
The Porta Nuova ('New Gate') opens onto Via Gracco del Secco, the main road in the old borgo, which is bordered by large residential palazzi. Their yellow plaster facades are in the late 18 C style and were added by Pietro Leopoldo di Toscana. Opposite one another are the hospital of San Lorenzo and the San Pietro conservatoire, with its adjacent church. Both of these buildings were built by the powerful Usimbardi family, to which the first Bishop of Colle di Val d'Elsa belonged.