Around 3500 BC new cultural values spread over the whole Sardinian territory. Sardinian habits change, and their way of life translates into new and original forms.
This id the beginning of the long history of the culture of Ozieri, the first great Sardinian culture.
Excavations have restored manufactured goods never seen until this time in Sardinia: vases like the "pisside" and the tripod, finely decorated with motifs engraved or stamped on the clay and often coloured with red ochre or white plaster. They are exotic manufactured goods for Sardinia in the neolithic period, but they are forms typical of the Eastern Mediterranean and the Greek islands.
The origin of the culture of Ozieri is, in , fact, eastern: these similarities, these cultural signs found in such far-off lands, demonstrate how frequent the relations between the neolithic peoples of the Mediterranean must have been. The people of the culture of Ozieri lived in villages: they built their houses on a stone wall, at the base, on which leaned a wooden and straws structure. What is left of these villages, the traces of the huts is still visible in the San Gemiliano locality of Sestu, near Cagliari and Cuccuru is Arrius, near Cabras .

The material used to make the arrowheads, the blades and the axes was always stone, mainly oxydian, but Ozieri man had learnt to work skilfully. This highly-skilled manual practice, the refinement and taste for decoration in pottery goods evidence community to us with an already advanced social organisation, in which a primitive division of work was present.

These men who loved refined objects and decorations left the most spectacular sign of their idea of life in the constructions destined to welcome the dead.
Their tombs, scattered all around the island, are of three types: Hypogeic, megalithic and circular.

The Tombs________________

Domus de janas
The hypogeic tombs, called in Sardinian "domus de janas" (Fairies' houses), are more than a thousand , spread all over the territory: these were genuine artificial grottos excavated in the rock, used as collective tombs, Some have only one room, others have a more complex structure with several rooms connected together. They are isolated, but often found together with necropoli, such as that of St Andrea Priu, near Bonorva (SS), Anghelu Rujiu, near Alghero (SS), of Pani Loriga, near Santadi (CA).

On the inner walls of some domus de janas, Ozieri man sculpted in the rock to produce the architectural parts of their houses and the daily objects of their lives: thus, still today details of roofs, ships, false doors, benches and beds are visible, almost symbolising the profound continuity between life on this earth and life after death. Occasionally, sculpted on the internal walls of the tombs, bulls' heads and horns appear, or enigmatic little circles : they are the symbols of God-Father and Goddess-Mother, symbols of the male and female sexual organs, the two cosmic forces generating life.

The Dolmen
The megalithic burial chambers, called "dolmen" (from the Breton "tol" = "tavola" + "men" ="rock), ares spread especially in the centre-north area of Sardinia: these were monumental sepulchres made up of three or more great rocks, planted vertically in the ground, supporting a horizontally-arranged boulder.

The dolmen are concentrated in the fields of the villages of Arzachena, Olbia, Luras, all in the province of Sassari, but they are frequent also in other areas: at Mores (SS) the well-preserved "Sa Coveccada" dolmen deserves a mention; in Dorgali is the dolmen of "Motorra" with a longer plan.

Circles
The "Circular" type tombs were were built only in a small area of the island, i.e. in the countryside around Arzachena (SS), in the Li muri area.
The circles are thus arranged : a certain number of rocks, fixed vertically in the ground, sectioned off an area at the centre of which, in some cases, though not all, stands a small quadrangular stone hut.

According to Giovanni Lilliu, the father of Sardinian archaeology, the dead were placed inside the circle so that their limbs could be deteriorate by atmospheric agents; once the flesh had rotten away, the bones of the dead were placed in the small house in the centre of the circle.
The presence of the circles only in the Arzachena area, used to persuade archaeologists that they were the expression of another culture, diferent from the culture of Ozieri, called Culture of the Circles.
Today archaeologists consider that the circles at Li Muri were built by Ozieri man: local diversity within a common cultural context ought not to surprise: it is a sign of the complexity and vitality of ancient Sardinian society.

The cyclical flowing of life and death, the birth of a new life as a result of the union of the male and female were at the heart of the religiosity if these men.
Actually, the god-Father and goddess-Mother divinities were widely represented, through the symbols of the bulls' horns and by the circular designs, inside the domus de janas, or else, more evidently, through the menhir (from the Breton "men" = "rock and "hir" = long, therefore literally being "long rock".

Menhir
In Sardinian menhir have the name of "pedras fittas" : they are great boulders, up to three metres tall, planted in the ground; they are found in various areas of Sardinia but are concentrated principally in the Barbagia. The rock of some menhir displays no sign or symbol: these are the icons of the male phallus, one of the two cosmic principles; on others, however, Ozieri man sculptured the

explicit signs of the goddess-mother, the breasts, feminine sign of fertility and life.
In Li Muri a "feminine" menhir with three breast marks, on its own, the complex, guarding the dead.
In Goni (CA) in the Pranu Mutteddu area, the menhir aligned in long rows are inserted in an area rich in Domus de Janas and of Neolithic rests.
Isolated or in groups these simple monoliths seem to have nailed to the Sardinia mother-earth, the ancient time in which they were erected.

Ozieri man worshipped the goddess Mother, as their Neolithic predecessors. They represent her with statues of marble and clay: the linear and geometric shapes recall the small statues of the Aegean islands, evidencing, once again, the cultural proximity between the East and West in the Mediterranean.

Towards 2700 BC the socio-cultural climate changes in Sardinia. In the final period of the Ozieri culture signs of this change are already evident: men who for centuries had decorated their pottery, lose the taste for the ornate and decoration disappears from their vases.