The pre-Byzantine building
In 1959, during the construction of the new Basilica, the Byzantine mosaics were removed in order to better preserved and relocated at the end of the work. On removing them, a surprising discovery was made: beneath the floor of the church and convent, various blocks of stone with painted and inscribed plaster belonging to an older religious building were found.
In particular, beneath the mosaic of the central aisle, right in the place where the small crosses and the monogram of Christ are depicted, a square-shaped basin cut in the rock with sides which are about two metres long and 1.6 metres deep and steps along the southern side was discovered. At the bottom of the basin, in the north eastern corner there is a circular well with a further hollow in the corner. In the wall plaster there are traces of the incisions made when the mortar was still fresh and interpreted by P. Testa as depictions of stairways (allusions to the "cosmic stairways"), crosses and boats.
The basin seems to have been closed and filled with various pieces of stone, ceramic dating back to the end of the 4th century and, in the upper layer, lots of fragments of white and coloured plaster bearing traces of graffiti written in the Syriac language. This basin is similar in shape to that of the crypt of Saint Joseph, but is not covered in mosaic. P. Bagatti, who initially thought it was designed for collecting wine, later decided that it was instead used for religious purposes. The similarity with that of Saint Joseph, led him to suppose that it was a baptism bath for Jewish-Christian initiation. Not all experts share this interpretation. More specifically, Taylor believes both the basins – of Saint Joseph and the Annunciation – more likely to be used for the village’s agricultural activities, for collecting pressed grapes for making wine.
Various building materials were found beneath the southern aisle and in the convent area. These were used to raise the level of the floor: pieces of painted and inscribed plaster, ceramics, illegible coins, fragments of roof tiles and pieces of marble slabs to cover the walls or floors. About seventy large architectural pieces were also discovered, including plaster, were also found that must have belonged to a demolished religious building: capitals, drums and bases of various columns made from local stone known as "nari", blocks which belonged to the arches of an aisle (double arch imposts), various worked cornices, door jambs and squared stones.