The nuraghi of Sardinia, of which Su Nuraxi is an example, are the best buildings for defensive purposes considering the materials and the techniques available in prehistory. In the Bronze Age (1500-800 BC), Sardinia develop the “Nuraghi”, construction in the shape of a truncated cone, built with stone, with interior rooms. Some, like the site of Barumini, whose central tower dates from about the 2nd millennium BC., surrounded by fences made up of towers linked by large walls. Around the defenses, small villages of circular houses. The central structures are erected by individual households or groups, to defend themselves from the Carthaginian incursions: in fact, the biggest nuragic settlements are located in that coastal area, or on the vast plain on the coast located to the east (as in the case of Su Nuraxi) more vulnerable to attack from the sea. The nuraghi become both defense centers and small urban settlements, self-sufficient communities with livestock, farming and handicrafts. In the 7th century BC, Su Nuraxi was sacked by the Carthaginians and the works of defense fall. It remains the settlement, reconstructed with different style: smaller stones and more rooms, which are also smaller. With the Roman conquest of the island in the 2nd century BC, most of the nuraghi were abandoned, although recent excavations have found traces of inhabitants until the 3rd century AD.