The 2005 excavation involved four areas. In the area of the colonnade and the strip immediately to its north a large collapse of opus vittatum mixtum incorporated in the uppermost levels of the late antique eruption was uncovered. This belonged to the tract of masonry on top of the colonnade, probably made up of platbands alternating with round arches, following a scheme similar to that of the adjacent walls and niches. The removal of the volcanic layers down to the ancient pavement level uncovered the column bases in white, Attic type marble, positioned on a stylobate made of grey lava blocks joined by metal gudgeons. The floor level north of the colonnade was 1.60m lower than the white mosaic pavement in the area between the structure with pilasters and the colonnade itself. Two flights of stairs in rectangular lava blocks, each with six steps, placed one at each end of the colonnade overcame this change in level. An underground structure with a square plan, defined as a cistern, built of regular courses of lava stone faced with opus signinum was also uncovered. Of the same phase but not connected to it was a small channel on a south-east/north-west alignment, below the level of the opus signinum floor, on a tangent to the cistern in the north-east corner. This evidence suggests the presence of a system for water collection, perhaps linked to the use of the tanks found in the southern area of the excavation (in 2003 and 2004). There were no elements which gave certain dating. However, on the basis of the pottery found in the abandonment layers in the area that were sealed by the eruption of 472 , a generic terminus ante quem may be set at the second half of the 5th century.

The investigation of the square room (called room 2) at the western edge of the excavation brought to light a further aperture to the west. This was later blocked by a small oven, found intact, built in the last occupation phases of the complex. The floor of the room was originally in opus sectile, of which only the impressions remain. These showed that the marble decoration had been reserved for the central part of the room, whilst the rest was paved with tesserae. Numerous bronze coins of the first half of the 4th century A.D. were also found.

The excavation of the area immediately north of room 2 revealed a wall on a north-south alignment, parallel to the room’s northern perimeter wall. In the area to the west and south-west excavation was limited to the removal of the volcanic deposits which uncovered a stretch of wall on an east-west alignment, in line with the southern wall of room 2 to which it was attached. (MiBAC)