The San Simeone archaeological complex is one of several archaeological, architectural, historical and monumental heritage in the municipal area. The area on which the historical complex stands is 625 metres above sea level, on the Su Monte plain, where the long anthropic continuity is proven by the presence of monuments that can be dated to a period running from the Nuragic Age to the Middle Ages. From this high plain, which was of great strategic importance, it was possible to control the route between the high plain of Campeda and Meilogu and the connections between the north and the western-central area of Sardinia (fig. 1).

Fig. 1 - The nuragic boundary area (from Wikimapia (reprocessing by M.G. Arru).

Here, there is a fortified site formed by eight megalithic boundaries (muras), including the best known ones Baddadolzu, S’Iligheddu, Mura Cariasa, Tilipera and Aeddo. The boundaries, controlled by the ruins of the Su Monte nuraghe, are close to each other and comprise strong walls that are 2 metres high and about 2.5 metres thick, round or trapezoid in shape, which are found by entering a rectangular entrance (fig. 2).

Fig. 2 - The Mura de Sos Alvanzales boundary (by TARAMELLI 1919, fig. 14).

The archaeologist Giovanni Lilliu identified these ruins as relevant to Nuragic Age structures, included in a huge fortified system that must have occupied several points on the Campeda high plain (fig. 3). During the Punic Age, this site was used as a castrum, and the muras, according to Lilliu, became guardposts for the Punic fortification.

Fig. 3 - Old photo of the Mura de Sos Alvanzales boundary (by TARAMELLI 1919, fig. 15).

On the edges of the plain, in the San Simeone area, a short distance from the muras, the area where the Punic fortress stood has been identified, dated to the 5th century B.C. Where the remains of two towers can still be seen, that protected the settlement from incursions by nearby populations. The site, due to its strategic position and proximity to the a Karalibus Turrem road, was probably used in the Roman Era as a military outpost.
The remains of the medieval village of Sanctus Simeon and the church of the same name located on private property on the plain that lead to “Su Monte” and the Campeda plain are also close to the muras. Today, the single-apse building is now rather deteriorated (fig. 4).

Fig. 4 - The ruins of the church of San Simeone, Bonorva (photo by Cinzia Olianas http://www.panoramio.com/photo/65011047).

The sanctuary, dedicated to San Simeone, was built around 1354 on the top of the high plain at Campeda that looks down to the Semestene valley towards Bonorva, and was certainly one of the first settlements of people in Bonorva. The inhabitants only stayed about thirty years, however, as due to the unhealthy nature of the area, they abandoned it to live further down the valley, where the first houses of the new town were built around a rural church. Some ruins of the houses still remain, with collapsed wall, reported rom the nineteenth century by Vittorio Angius and Alberto La Marmora and erroneously attributed to the Roman Age, and some arches from the chapel dedicated to the saint.