The Cathedral, dedicated to San Lorenzo, was built under the supervision of the Sienese architect Sozzo Rustichini. The construction began at the end of the XIII century and the Church was completed between 1330 and 1340. However, the building went through an extensive renovation in the XVI century and a restoration, which continued throughout the XIX century. The façade features the symbols of the Evangelists, ascribed to Sozzo and Agostino di Giovanni; the right side, which looks on to Piazza Dante, is characterized by a fourteenth-century ornamentation, with the exception of the upper part of the portal, completed in 1897 by Leopoldo Maccari. The interior of the Cathedral features two fifteenth-century glass windows, attributed to Benvenuto di Giovanni (around 1470), the Madonna delle Grazie (Our Lady of Graces) by Matteo di Giovanni, the baptismal font and the marble aedicula of the Madonna delle Grazie, both the work of Antonio Ghini (1470). The main altar was consecrated in 1655 and completed in 1692 with the ciborium, the work of the Sienese artists of the Mazzuoli family.