Saint Charles of the Lombards church
You can reach the church of San Carlo dei Lombardii from Piazza del Duomo by walking down via dei Calzaiuoli and then, on your left, via dei Tavolini.
Address: 7 via dei Tavolini
Price: free of charge
Beautiful church with a single nave whose apse is divided into three by pillars supporting pointed vaults, decorated with beautiful frescoes.