Their peculiar shape gives an anthropomorphic appearance to the rock, almost as if it were watching over the extraordinary testimonies of the remote past with a severe countenance. The four domus de Janas of the Filigosa necropolis rise at the foot and on the slopes of a hill topped by the imposing tower - 13 meters in diameter - of the Ruiu nuraghe. The pre-nuragic burial ground is a few kilometres from Macomer, the main centre of the Marghine, and is closely linked to that of Abealzu, in the territory of Osilo. Although they are 60 kilometres apart, the two sites, Macomerese and Osilese, have architectural similarities, in terms of type of burials and identical finds: from the two necropolis derives the name of an important cultural facies of the Sardinian Eneolithic, the culture of Abealzu - Filigosa - also known only as Filigosa -, developed between 2700 and 2400 BC
Four tombs have been investigated so far: three dug into the tufa at the foot of the hill, and the fourth to a higher level, although the original the number of burials had to be much higher. All are multicellular, characterised by long access dromos (corridors) that follow the natural inclination of the rock and have circular hearth cells in the centre of the floor. The necropolis was used by the proto-Sardinian populations up to the first centuries of the II millennium BC, with funeral rites that provided for scarification and burial of the remains in secondary deposition (not in physiological position). The dromos of tomb I, eleven meters long, leads to the trapezoidal main compartment: at the base of one of its southern walls you will notice a funeral bed and, higher up, two hemispherical cups. At the centre of the floor stands a hearth of one meter in diameter with an annular edge in relief and central dip. Two doors in the back wall lead to six secondary cells. The first leads into a polygonal space and from this to another rectangular area; the other door gives access to four compartments arranged in pairs, one of which is in turn divided into two parts by a 'partition'. The dromos of tomb II has an initial curvilinear development, a trapezoidal major cell and other three square rooms connected in horizontal succession. The main cell, with a sloping ceiling towards the entrance, presents the 'classic' ritual fireplace and niche on a wall. The corridor of the third tomb, ten meters long, grows in height and width towards the bottom, covered in the final stretch by a small pavilion. The door with negative frame of the back wall leads into two coaxial square rooms. Tomb IV also has a corridor followed by three coaxial and square cells - with fireplace, cup marks and small niche - while a fourth side compartment opens onto the second room.
Of great interest is the reuse of the first tomb in the Nuragic age, with the restructuring of the dromos prospect with well-shaped ashlars, almost simulating the entrance of a Giants' tomb. The excavations have also brought to light a half-metre deep well, full of ceramics and Roman fictile objects of the Republican and Imperial ages. Macomer, not by chance, is identified with Macopsissa, the first Punic and then Roman city, cited by the geographer Ptolemy (2nd century AD), a strategic place of passage between the south and north of the island. Traces of streets and milestones remain.
In addition to Filigosa, among the prenuragic funerary complexes, Perdas de Tamuli stands out. The Macomerese territory shows traces of settlement dating back to the Upper Palaeolithic period, in particular in the Marras cave, where a statue of the Mother Goddess ('Venus of Macomer') was found, kept in the national archaeological museum of Cagliari. Among the nuragic testimonies, in addition to Ruju that dominates the necropolis of Filigosa, the most impressive and famous is the nuraghe of Santa Barbara, consisting of a 15 meter high central tower, a four-tower bastion and a large village. The Giants’ tomb of Puttu 'e Oes is also worth a visit.