Situated on the state road, the church of Porto di Mezzo is quite recent and derives from a small oratory, built at the request of the devoted faithful.
Chronicles report the existence of a small oratory on this site in the 16th century. It was consecrated to Saints Sebastian and Rocco and managed by the brotherhood of Saint Rocco. An inscription at the entrance of the church reports that works to enlarge and restore the building began in 1730 and were funded by the brotherhood.
The grey-stone altar on the left is consecrated to Saints John the Baptist and Peter and was constructed by the Fancelli family in 1743. The altar on the right dates from 1772 and is dedicated to the Virgin.
Between 1745 and 1747, the oratory housed the mortal remains of a martyr, Saint Giustino, sent from Rome.
Historical records lack information on works of art the church housed and today the only painting is the one attributed to Antonio del Ceraiolo, brought from the church of Santa Maria delle Selve.