The archaeological site of Piana S. Marco is situated within the national park of Gran Sasso and the Monti della Laga. The area is characterised by a continuity of occupation attested by the Italic settlement of Colle della Battaglia, the remains of an imperial villa or pagus and the necropolis of Monte Piasatro.

The investigation looked at the area of the monastery, attested for the first time in a bulla of Pasquale II of 1112, but probably dating to the 9th century, when Marcianisci is first mentioned as being under the control of San Vincenzo.

The areas examined were situated next to the southern perimeter of the church of S. Marco (Sect. I), next to the southern and eastern perimeters of the tower (Sect. II-IV), between the tower and the church of S. Marco (Sect. III), in the south-eastern interior corner of the church of S. Marco, partially including the area spanned by the door (Sect. V), in the north-western corner of the internal space between the church and sect. III used in recent times as a dwelling (Sect. VI). The occupation phases attested at the base of the podium of an imperial temple, consist of walls which reused materials dating to the period of the Graeco-Gothic war (mid 6th century), a reinforcement of the temple now identified as the Capitolium during the Byzantine fortification, a 6th century mud hut and a hoard consisting of six silver coins and a solid gold aureus of Justinian in a very good state of preservation. The site of the hoard find, a cavity in a wall, and the date of the main coin (mid 6th century) suggests that it was hidden during one of the Ostragoth invasions.

In sector I an opus signinum floor was uncovered which overlay a make up of imbrices placed edgeways up. The floor rested directly on several large limestone ashlar blocks belonging to the temple.

A cemetery was created around the small church, in the medieval and post-medieval periods, with “a cassone” burials, multiple burials and earth grave burials. During the 18th century the cemetery was cut by a large limekiln with a circular base and praefurnium, used during the restoration of the church. The western half of the limekiln had eroded the temple podium whose remains were probably used to produce lime.

Sector IV of the excavation produced a large quantity of pottery datable to between the 5th and the end of the 6th century A.D. In zone E of this sector the layers of fill were removed from a large pit (containing material datable up until the 19th century), covered by a beaten mortar surface. This was interpreted as the result of an unsuccessful attempt (19th century) at robbing the blocks, as attested by a number of blocks that were still in situ. The excavation of the robber trench brought to light the lower courses of blocks of the temple.

The investigations undertaken in June-July 2007 involved sector I, exploring the limekiln’s preafurnium, and sector II with the identification of a burial in an earth grave on a north-south alignment. In sector II a mud wall with a stone footing belonging to a rectangular room was uncovered, dating to the Byzantine occupation of the site. A layer of earth and small cobbles to the south of the tower may relate to a cobbled surface, probably in phase with the mud-built structure. Amongst the materials found were fragments of late antique pottery, shoe buckles and glass fragments.