The church of San Francesco was originally a Benedictine Church dedicated to San Fortunato. In 1289 the Church was consigned to the Franciscans, who renovated the ancient part of the complex according to the architectural style of their order. The main body of the Church is covered by a roof trusses and has a rectangular apse. Outside, the portal features a rose window depicting the Madonna col Bambino (Vergin and Child) and the Saints Fortunato and Francesco, work of the artist Giuseppe Casucci (1877). Inside, the church contains fragments of frescoes of the Sienese school (XIV and XV century), among them a fresco of Saint Anthony Abbot on the throne and a huge fresco of Saint Christopher Carrying the Christ Child. Above the main altar hangs a crucifix traditionally attributed to Duccio di Boninsegna, but recently ascribed to Guido Graziano (around 1260-1280). Attached to the church is a huge convent, which was significantly reduced in size when the Medicean Walls were built at the end of the XVI century. On that occasion the convent was renovated and the event was commemorated with an inscription on the well at the centre of the cloister with the name of the Grand Duke Ferdinando de’ Medici and the year 1590.