Grotta di San Michele, Cave church in Faicchio, Italy.

Grotta di San Michele is a natural cave on Monte Monaco di Gioia, in the municipality of Faicchio, at about 500 metres' altitude. Its semicircular opening is six metres high. Inside, a stone staircase forks up to a first chamber used as a church, 10 metres wide, 6 long and 5 high, with stalactites and stalagmites; a second chamber keeps 12th-century frescoes, and a third is rich in limestone formations.

The Lombards adapted the cave for the cult of the Archangel Michael around 700. In the 12th century it was restored and decorated with frescoes, and it was solemnly inaugurated in 1172. In 1446 it was attached as a simple benefice to the collegiate church of Santa Maria Assunta in Faicchio; by 1596, when Monsignor Savino wrote his note, Mass was no longer celebrated there.

The cave's name comes from the Archangel Michael, to whom the Lombards dedicated it around 700. A 2002 ceramic panel from Cerreto, set above the entrance door, shows Michael dominating the devil with the sword and the scales used to weigh souls. Inside, the 12th-century frescoes include a Madonna and Child with the Greek initials "MHR OU", Mother of God.

The cave has no road access: it can only be reached on foot by two trails, one from the convent of San Pasquale (about 2.5 km with roughly 400 m of elevation gain) and one from Fontanavecchia. Near the entrance stands a late-18th-century refuge with two stacked rooms, and the surrounding area has benches and barbecues for stops.

The cave's second chamber holds a well that collects water dripping from the stalactites. Its 12th-century frescoes, painted by a single artist with clear Byzantine influence, include a Madonna and Child with the Greek initials "MHR OU" (Mother of God) beneath her. Humidity has left them poorly preserved.