Piazza San Giacomo is dominated by the façade of the church, which gives it its name, and the adjacent Servi di Maria convent. Built between 1200 and 1300, as attested by the ogival portal, the church was later renovated in the 17th and 18th centuries. Inside the convent is a valuable cloister and lunettes depicting a cycle of frescoes representing scenes of St Filippo Benizzi. The opposite side of the square is dominated by Palazzo Andreozzi, which houses the diocesan historical archive and the Ludovico Jacobilli library. From the Church of St Giacomo, one accesses Via Mentana, along which we find the church, the vegetable garden, and the convent of the cloistered nuns of Santa Lucia, a complex of buildings dating back to the 15th and 16th centuries. The street ends with the Jacobilli Gardens, where the peculiar bulk of the Cinque Cantoni Tower, which now houses the astronomical observatory, stands out.