The chapel, dedicated to Santa Barbara, was built in the thirteenth and fourteenth century, inside a feminine convention complex of Clarisse and Benedictine, of which ruins in the vicinity are used for agricultural purposes. The facade has an entrance door with a monolithic architrave surmounted by a lunette, probably once painted. Above the lunette was a rose window, now occluded by blocks of tuff. The chapel has a unique rectangular interior plan with a semicircular apse. The latter appears barred by tuff blocks, from the destruction of the apse, facing east. Along the north wall is a door that connected the church with the adjacent monastic area.  Traces of preserved frescoes are really rare: on the northern wall are traces of a Deesis: Mary, Christ and St. John the Baptist, relevant to the first phase of decoration, still of a Byzantine style, from the beginning of the fourteenth century. Other traces, including a well-preserved image of a saint, date back to mid-fourteenth century. On the southern wall are two full-length Saints: Santa Barbara, with her usual iconographic attribute of the tower in the right hand, and San Bernardino of Siena, certainly from the mid-fifteenth century.