The 2005 archaeological investigations at the monastery of S. Pietro looked at two sectors.
Sector I is situated in the south-eastern part of the complex; the structures delimit a space divided into two parts (rooms 2 and 3) on present floor level and a third (room 1) on a raised level. Room 1 has three windows, not intact, two on the west side, one on the east side. Of the fresco only isolated parts of the plaster survive. The first level relating to room 2 was created from four different levels which sloped towards the vault and served room 3 which was on a single level. Room 3 was delimited by three walls to the north, east and north-east and like room 2 has a beaten floor above a layer of mortar and broken stone placed over an earth fill. Room 2 was rectangular and closed on four sides and must have had an opening on the west side.
Sector II was investigated for the first time in 2005 and involved room 1. This is formed by a narrow rectangle over 22m long and 7m wide, on an E-W alignment. It was closed on four sides by structures with a double curtain, which are not very well preserved, with rough hewn ashlar blocks, bonded with mortar that was smoothed between courses.
The find of two circular column bases similar to those found in room 2 of sector I is of interest, even though, unlike those in sector I, the columns from sector II are aligned and in a central position with respect to the room they are in. The lower parts are made of stone from the Maiella mountains, the drums in travertine and they present two or three courses of shaped ashlar blocks forming a circle with a diameter of c. 1m. The foundation ledge, 1.50m in diameter, rests on the mortar and stones and is made of small pieces of broken stone bonded with mortar. (MiBAC)