Together with the primitive sanctuary, to be identified as a square building three-lobed internally, with to the west a porticoed courtyard, on the highest point of the mountain, we have to include the mosaic floors of the areas to the west, north and south of the cella trichora. Stratigraphically speaking these areas can be divided in two chronological phases, not too distant from each other, between the second half of the IV century and the first half of the V century.
In relation to the first phase we can include:
- to the west, the mosaic of an area in which three tombs and a cistern were excavated. To these one has to add the mosaiced area at the centre of the courtyard of which only an angle enclosed in a line of black tesserae survived, and the mosaic of the Cross.
-to the south, the mosaics with the dedicatory inscription, the mosaics decorated with a polychrome panel, and the mosaic of the small external area beyond the VI century basilical complex.
- to the north the mosaic which extended to the west towards the exterior of the basilical complex in relation to the cistern in the corner of the front courtyard.
To the second phase, characterized by a refurbishment of the antique edifice and changes to the surrounding areas, belong the following:
- the polychromed mosaic of the cella trichora which remained in use throughout the life-span of the sanctuary.
- the mosaic of the area to the North and that of the funerary area, also to the North, together with the mosaic in the portico on the northern and southern sides of the central courtyard in front of the west side of the sanctuary.
Most of the mosaiced floors of the primitive sanctuary present similar characteristics. On the technical side the tesserae are of the larger white type (6 tesserae in 10 linear centimeters) arranged diagonally and laid down on a fine layer of lime and ashes directly on the tufa of the mountain. The mosaic panel is usually enclosed by one or two contour lines which follow the perimeter of the areas and the eventual protruding structures like the pillars for the arches supporting the ceiling.
The plain white background of the composition, functional for the practical use of the areas, is only varied on certain occasions by polychrome decorative motives.