Rooms VII and VIII are dedicated to the XVIII Mountain Community and the most important sites uncovered during the modifications to the S.S. 131.

Of great significance are the funerary context of the Bell Beaker period at Padru Jossu, the Nuraghe Corti Beccia, the Punic-Roman necropolis of Bidd'e Cresia (Sanluri), and the area of Su Fraigu (S. Sperate), with ceramics from the Monte Claro culture and Nuragic ornaments.

Numerous and valuable artifacts, dating from the Nuragic period to the Early Middle Ages, come from the territories of Serrenti, Samassi, San Gavino, Gonnosfanadiga, and Arbus. Particularly important are the Punic terracotta ex-votos from ancient Neapolis, located at Santa Maria di Nabui (currently in the Guspini area).

The visual museum path is complemented by a tactile route with captions, a Braille catalog, and an audio guide, aimed at assisting low-vision and blind visitors.