VALLEPIETRA, SANTUARY OF THE HOLIEST TRINITY OF. — It is in the valley of the Simbrivio, near the Colle della Tagliata which leans against the southern flank of Monte Autore (diocese of Anagni). Here, on a small ledge, a grotto penetrates into the bowels of the mountain, in which the Sanctuary is situated (in the Holy Trinity it is represented under the semblance of three human persons).
The most important pilgrimages of the year occur on the feast of the Holy Trinity and that of St. Anne. The origin of these is very ancient; the graffiti of visitors date back to the 15th century. In 1850 the number of pilgrims was estimated at ten thousand; today it is about one hundred thousand, 70,000 on the feast of the Holy Trinity and 30,000 on the feast of St. Anne. On this occasion, the pilgrims sing the miracle worked by St. Anne for the three orphans. A representation of the Passion of the Lord, called “piano delle zitelle,” is performed, on the occasion of the feast of the Holy Trinity, on the loggia of the Sanctuary by some women from V.
The origins and most ancient events of this Sanctuary are unknown. It is probable that the grotto was a pagan shrine dedicated to nymphs or river deities: votive offerings have been found near the grotto. After having combated the pagan cult, Christian worship substituted its own rites. When this occurred is not known. Some believe that the substitution was the work of pre-Benedictine Greek monks. An Eastern influence is supported by the Eastern names of some surrounding localities and by the cult of St. Anne. Another hypothesis may be that the Basilian monks of Grottaferrata, who took refuge in Subiaco in 1183, built a monastery near the grotto, whose existence is attested by ruins and various indications. The church of the Holy Trinity of V. is mentioned for the first time in a document of 1119 in which a donation made by a citizen of Trevi to said church is recorded. In 1294 Peter, bishop of Anagni, united the church of the Trinity to the Chapter of the cathedral of Anagni to increase the revenues of the canons. In 1658 Horace Caetani, lord of Vallepietra, elevated said church to the status of an abbey, reserving for himself the right of appointing the abbot. At present the Sanctuary is administered by the episcopal curia of Anagni.