They are the places of Byzantine and Longobard period, brought to light thanks to the excavations promoted by the Archdeacon of the Chapter, Nicola Quitadamo, in the years 1949-1960. They used to serve as the entrances to the grotto and were definitely abandoned in the 13th century, at the time of the Angevin constructions. Many inscriptions along the walls of the “crypts”, some of Runic characters, testify to the considerable influx of pilgrims since the Longobard epoch.

Lunghe circa 60 metri, si sviluppano fin sotto il pavimento della Basilica. L’ambiente giunge fino al possente muro di sostegno sul quale, nella parte superiore, sono poggiate le famose Porte di bronzo. Questa prima parte appare come una galleria porticata coperta da volte a botte. Qui sono esposte diverse sculture provenienti dagli scavi del santuario, dall’ex chiesa di San Pietro e dalle rovine dell’abbazia benedettina di Santa Maria di Pulsano.

The “crypts” are composed of two rooms whose structures had to be made in two phases following immediately one after the other.

Some of the wall inscriptions, identified in 1974, have made it possible date the constructions from the end of the 7th to the beginning of the 8th century. The crypts, about 60mt. long, extend up to beneath the floor of the Basilica.

The first room, about 45mt. long, comes up to the mighty supporting wall on which, in the upper part, the famous Bronze Doors rest. This first part seems like an arcade, made up of eight rectangular spans, communicating with each other through transversal arches, that detach from large pillars that jut out from the side walls. It is all covered with a barrel vault. Besides, during the work undertaken by the Benedictine Fathers in 1975, was discovered a mortuary cell with two sarcophaguses, one of them has not been opened; it has got a cover in mortar and a graffito cross dated 7th-8th century. In this suggestive room, various sculptures from the excavations of the shrine, from the ex-church of St. Peter and from the ruins of the Benedictine Abbey of St. Mary of Pulsano have been put on exhibition. All the finds exhibited here are dated from the 7th-8th century up to the 15th century.

Throughout the visit, pilgrims can admire a variety of finds that, once more, give witness to the glorious history of this place. Here are some of the most significant ones: the coat of arms of the City of Monte Sant’Angelo that dates back to 1401; different architectural elements (11th-12th century) such as fragments of columns, mullions in local stone, decorative elements; a Madonna and Child dated 15th century; a statue of St. Michael of the first half the 16th century; a statue of the Saviour dated 15th century; a font decorated with biblical scenes; various fragments of a pulpit, among which an eagle – dated 11th century – with lectern made in the atelier of local sculptor, Archdeacon Acceptus; fragments of pluteus (10th-11th century); a funeral cross (8th century); another sculpture representing St. Michael (14th century); an Angel with a standard (10th-11th century); a praying Christ (11th-12th century) and, of the same period, a headless Madonna. In one of the small rooms are housed some spiral columns with capitals dated 10th-11th century, a stiliforo lion of the same period, a paving-stone (8th-9th century); slabs of terra-cotta for tomb coverings, attributed by some to the 8th-9th century, by others to the Roman era; finally some fragments of paving-stone with graffiti that go back to the year 1066.

Passing through the opening excavated in the sustaining wall of the Bronze Doors, we find ourselves in the other room of the Longobard epoch, divided into two large naves, each one of them made up of a central flight of three round arches, and delimited at the north and south by other arches sustained by massive pillars. The roofing of this room was supposed to have been composed of a barrel vault sustained by transversal arches. The two naves were occupied by stairs: the one on the right has a curvilinear trend and is preserved integrally in its course; the one to the left had a rectilinear trend, but was completely destroyed during the work. The two stairs ended into a small floor, delimited to the east by an apse with an altar made up of squared blocks with traces of numerous inscriptions, to the north by some rooms whose entries were obstructed, and to the south by two entrances that gave onto the rocky slope opposite the grotto.

To the left of the altar a fresco called the “Custos Ecclesiae” has been discovered, protected by stone slabs that can be attributed to the 10th century. At present it is exhibited in the Conference Hall. From the remains of the frescoes and from the numerous inscriptions on the walls, we can understand the importance of the Shrine, especially for the Longobards.

These rooms were definitely separated from the Sacred Grotto towards the years 1270-1275, when the Angevins gave the current arrangement with the new constructions, sacrificing the preceding works built in honour of St. Michael Archangel.