Pre-Nuragic Altar of Monte d'Accoddi is located near Sassari. The pre-Nuragic sanctuary is located in the center of the Nurra, along the 'old' state road 131 (towards Porto Torres), in the territory of Sassari, eleven kilometers from the northern capital of the island. The monument had a central role in the society of the time: it was the culmination of the evolution of a complex that developed from the second half of the fourth millennium BC The altar is the superimposition of two phases, that of the 'red temple', in the final Neolithic (3500- 2900 BC), and the later one of the 'stepped temple', in the Eneolithic (about 2700 BC), during the 'culture of Abealzu-Filigosa'. All the stones had a precise function in the sacrificial rites. At the end of the final Neolithic, the people of the 'Ozieri culture' built a platform in the shape of a pyramidal trunk, with sides at the base of 27 meters, above which stood a rectangular compartment with surfaces plastered and painted in ocher and traces of yellow and black. Of the sacred environment only the floor and the remains of a perimeter wall remain. Around 2800 BC, the structure of the 'red temple', abandoned for about two centuries, was covered with a colossal filling of earth, stones and limestone marl, in turn 'covered' by large blocks of stone. A new large 'stepped' pyramidal platform was built, with sides longer than the previous one and accessible by a ramp, forty meters long and thirteen to seven meters wide. The second sanctuary recalls the ziqqurat with an 'open-air' altar.