Cuccuru is Arrius was a thin sandstone outcrop -whose formation dated back to the Quaternary Era — located on the southern shore of the pond of Cabras, today almost completely removed because of the construction of the drainage canal which serves as a link between the before-mentioned pond and the Gulf of Oristano. Man settled there since the Middle Neolithic (culture of Bonuighinu: 5th millennium BC), as evidenced by the Necropolis in which the dead were buried in artificial cave tombs. In particular, they were laid down on their left side in contracted position, accompanied by rich burial goods, including pottery vessels, stone tools (greenstone hatchets, obsidian geometric microliths) and ones of bone (spear tips), as well as female figurines. The dead were also adorned with necklaces made up of minute chlorite wheels and shells.
Two display cases of the Museum are dedicated to the recent excavations of the Nuragic village of Sa Osa led by the Archeological Superintendence of Cagliari and Oristano. The village of Sa Osa was populated for a very long period. Initial phases of settlements date back to the Copper Age (3rd millennium BC), then settlements developed mainly in the Nuragic period, from the Middle Bronze Age (1700-1365 BC) until the Early Iron Age (9th -half of the 8th century BC).
The site is situated on the plain of Campidano Maggiore, about 2 km from the current coastline of the Gulf of Oristano and about 500 m from the right bank of the Tirso River. It also occupies a slight floodplain at 6 m above sea level, which slopes south towards the bottom of the river valley, the so-called Bennaxi. The site is about 200 m from the village of S’Arrieddu, where a settlement of Ozieri facies (4th millennium BC) is located, and a lithic cist grave of the Beaker and Bonnannaro culture (late 3rd-early 2nd millennium BC) was found.
The necropolis of Monte Prama is located at the base of the hill that bears the same name, at a distance of about 2 km from the town of Cabras, along the road that leads from San Salvatore to the town of Riola Sardo. After the accidental discovery of the site in March 1974 by peasants farming in the area, several excavation and recovery missions followed between 1975 and 1979, conducted by the Superintendency for Archaeological Heritage of Cagliari and Oristano and the University of Cagliari.
The first excavation was conducted in 1975 (under the direction of A. Bedini) and identified a dozen graves consisting of lithic cists (small stone-built coffin-like box) with square and circular pits, some of which are considered to be Nuragic ceramic artifacts. In the second official dig, conducted between 1977 and 1979 (under the direction of C. Tronchetti), thirty more graves, aligned in a single row from south to north, were discovered, along with three more to the east.
A section of the exhibition dedicated to the city of Tharros, founded by the Phoenicians between the 8th century and 7th century BC and populated until the Middle Ages, offers a broad picture of the results of various archaeological excavations conducted primarily in the tophet and in the Punic industrial workshop area.
This section displays the archaeological finds from the tophet, the typical public Phoenician-Punic sanctuary, consisting of a large open area, surrounded by a sacred enclosure in which were placed urns containing cremated remains of children and small animals. The tophet was discovered in 1962 and explored in the years 1962-63 under the direction of the Archaeological Superintendence of Cagliari and Oristano (G. Pesce, F. Barreca) and between 1974-1986 by a mission of the CNR of Rome (A. Ciasca, E. Acquaro).
The last section of the museum, which opened on 7 June 2008, is dedicated to one of the most important underwater discoveries of recent decades, a shipwreck in the stretch of sea between the coast of Sinis and the island of Mal di Ventre that occurred during the 1st century BC. The shipwreck was discovered in 1989 and was subsequently surveyed and excavated from 1989 to 1996 by the Archaeological Superintendence of Cagliari and Oristano, in collaboration with the National Institute of Nuclear Physics of the Gran Sasso.
The wreck, which lies on the seabed at a depth of about 100 feet, is located 6 miles from the coast and just over a mile southeast of the island of Mal di Ventre. It owes its extraordinary archaeological importance to its contents, which included a load of lead ingots, the biggest quantity of such ingots documented in the ancient world. It is assumed that the ingots were a part of or the main cargo on the ship.