Built by municipal will starting from 1390, designed by Antonio di Vincenzo. The central portal is the work of Jacopo della Quercia (1425-38); the lunettes of the lateral ones are by A. Lombardi (Resurrection, 1525) and by A. Aspertini (Christ deposed, 1526). Inside are paintings by Giovanni da Modena (1410-15), L. Costa (1492), A. Aspertini (1519), Parmigianino (1529), L. Pasinelli (1672-86), VM Bigari (1736-52 ), G. Gandolfi (1779). On the floor there is a large sundial traced by Gian Domenico Cassini in 1655.