Carved in a natural trachytic amphitheatre dominating a fertile plain;Montessu is one of the most important prenuragic necropolises in Sardinia.It consists of about forty domus de janas tombs (literally “witch house” or “fairy house”);with different plan and dimensions.Two tombs in particular;considered as sanctuary-tombs for the cult of the ancestors;are impressive for their dimension and architecture:Sa Cresiedda (“the small church”) and Sa Grutta de is procus (“the cave of swine”);on the hedge of the rocky amphitheatre.They are characterised by a semicircle of megaliths on the front;2m high entrances and a big pavilion used as vestibule;which leads through three openings into the tomb area.This last is divided by robust partitions whose closures are set in a spiral shape symbolizing the eyes.Two other tombs;not so impressive but very important for their religious symbology;are the so- called “spirals’ tomb” and “horns’ tomb”.They show rich carved or in relief decorations:red ochre “wolf’s teeth”;the colour of blood and regeneration;spirals which symbolise the eyes or the breast of the Mother Goddess;;festoons;curvilinear and candelabra- shaped patterns;a false door to the afterlife;different shaped horns related to the Bull God cult.The necropolis dates back to the Late Neolithic age;the Culture San Michele di Ozieri (4th millennium BC) and was frequented until the Nuragic period (15th-10th century BC).