The standing columns of the Hellenistic sanctuary of Monte Rinaldo in the heart of the Marche countryside mark the site of an important centre within the regional archaeology of the Piceno region, and one about which remarkably little is known. The decision to re-erect part of the collapsed colonnade following its excavation in the 1950s has restored the strong visual impact of the site, but has raised a number of issues regarding the correct architectural reconstruction of the site. The portico, which rises unexpectedly in the midst of the agricultural landscape typical of this area in the mid-Adriatic, provides the visitor with a strange phenomenon, but one which encourages discussion as to the historical and topographical significance to the location of such a building. The earlier research, which provided the first complete interpretation of the site placing it within the Roman–Hellenistic architectural tradition, left many unanswered questions: the comprehension of the various phases of occupation of the site, the precise articulation of the complex and above all its historical significance and place within the wider archaeological study of the countryside are all aspects which still need to be fully explored and understood.

In 2016, as part of a wider agreement aimed at developing a joint research programme along the Adriatic coast, the British School at Rome, the Department of History and Culture at the University of Bologna and the Centro Studi per l'Archeologia dell'Adriatico di Ravenna (ARCADRIA) began a new integrated research project for the study of the sanctuary of Monte Rinaldo (2^nd–1^st century BC), with the aim of restudying the archival documentation and to restart work on the site. The project, directed by F. Demma, E. Giorgi and S. Kay, forms an extension of an existing research agreement between the University of Bologna, the Soprintendenza Archeologia, Belle Arti e Paesaggio delle Marche and the Comune di Monte Rinaldo. Between 2012 and 2015 a team from the University of Bologna began work on the topographical analysis of the ancient Via Salaria Gallica which connected Ascoli Piceno (Asculum) and Fermo (Firmum).

In the spring of 2016 a first research campaign by a joint team from the BSR and University of Bologna was undertaken at Monte Rinaldo with the collection of archival data, the topographical planning of the site with GPS and geophysical prospection (magnetometry), laser scanning of the architectural elements, photogrammetry of the architectural sculptural elements and analysis of the material from the earlier excavations conserved at the museum. In the summer of 2017 a new series of excavations was commenced with the aim of better understanding the conserved stratigraphy.

The complex is sited on the eastern side of the Val D'Eso, on the boundary between the territories of the Latin colony of Fermo (264 BC) and the federal city of Asculum, on a terrace that dominates the valley. In its final construction phase (2^nd–1^st century BC) the terrace was bordered by a Doric portico on three sides (porticus triplex) and placed within the centre was a Tuscanic temple, tetrastyle with three cellae (Fig. 1). Two brickstamps and graffiti on some black glaze bowls, together with some terracotta tiles representing winged lightning bolts, allow the conclusion that the principal cult was dedicated to Jupiter, with other secondary divinities such as Hercules present on the front statuary cycle. The sanctuary today appears to be isolated and it is not yet known if it was surrounded by a settlement which is unknown archaeologically. In this territory, between the Adriatic coast and the Apennines, a Roman town has yet to be identified which may have performed the function of governing the territory typical of the system of the Roman prefecturae of the Republican period (3^rd to 2^nd century BC), which was later the basis for the development of the municipia (1^st century AD). One of the hypotheses being considered is the role that the sanctuary may have performed in the organisation of the local rural population as a central place.

Fig. 1. Plan of the sanctuary of Monte Rinaldo (Plan. F.Belfiori).

The excavation, undertaken in June and July 2017, focused on two areas in front of and behind the temple. The first area concentrated on the space between the temple and the rear portico with the aim of verifying the presence of any remaining undisturbed archaeological stratigraphy as well as any further parts of the collapsed architectural structure. The second excavation area was placed in front of the temple, with the aim of verifying the extension of the lateral parts of the portico and the area behind the podium. Furthermore, several test trenches were excavated inside the cella of the temple and two trenches, a few metres in front of the temple, were excavated with the aim of recording any remains of the altar or other structures which would help with the reconstruction of the entranceway to the higher terrace. Unfortunately, no further structures were brought to light. In all the excavation areas it was possible to confirm the frequent modern reconstruction of the ancient structures, confirming the findings of the study of the documentary archive. However, despite the modern restoration, several large areas of the surviving undisturbed stratigraphy were recorded. This has permitted the confirmation of the construction phases hypothesised on the basis of the study of the material recovered from the earlier excavations. Furthermore, several pieces of the collapsed architectural decoration and several diagnostic ceramic fragments were recovered from the surviving stratigraphy. Parts of the collapse of the northern portico were brought to light behind the temple, which in turn covered a layer which contained both Roman black glaze ware and Picenean coarseware. Furthermore, trenches inside the central and southern cellae of the temple revealed that the foundations cut earlier layers containing coarseware predating the Roman occupation, which confirms the earlier frequentation of the site. In a few examples the material dates to several centuries before the Romanization of the Picenean area (3^rd century BC). However, in other areas it is not clear if this was residual material or whether the pottery was still used within the contemporary material culture.

The current research suggests that the architectural complex was built over the course of the 2^nd century BC in a sacred area probably already frequented before the first Latin colony of Firmum (264 BC). The presence in the same layers of coarseware material with a Picenean origin and black glaze pottery imported from Lazio represents one of the most interesting ongoing studies. For this reason, it is not known with any certainty if the area was already used as a sanctuary of which there is no trace or which did not have a roof (sub divo) before the imposition of the colony or whether the remains of the material culture of Picenean origin represent a case of the persistence of use, such as has been attested at the Santuario dell'Annunziata at Ascoli Piceno. The original plan, of the first half of the 2^nd century BC, was formed by the temple and the rear portico, whilst the side porticos and the sacello, connected to a spring and the cultural use of water, were built in a slightly later phase. In the 1^st century BC the complex was heavily rebuilt, with a ritual reuse of some architectural elements of the first building phase, and the rear portico was enriched with two side wings with Ionic columns. The understanding of the architectural complex is associated above all with the discovery of numerous fragments of its architectural decoration, either in layers of collapse or reused in the later construction. It would seem that already in the early Imperial period the sanctuary was destroyed and was not rebuilt. In its place a cemetery (1st century AD) and a farm were built (2nd century AD) reusing much of the architectural material from the sanctuary. This material was recovered when the first excavations took place under the direction of Annibaldi at the end of the 1950s, which dismantled the ancient structures and began a reconstruction with little attention to the original form. The material was distributed between the local museum of Monte Rinaldo and the National Museum at Ancona. The study of this material and that recovered during the new excavations, led by Francesco Belfiori, will allow the careful reconstruction of the architecture and building phases of the temple, the sacello and the surrounding portico. As the archaeological finds are conserved within a park open to the public, one of the objectives of the project is also the sharing of the results of the research and its virtual reconstruction.