Start your journey in Quartu Sant’Elena, where you can visit the Nuraghe Diana. It is a well-preserved Nuragic site that dates back to the Bronze Age. The Nuragic culture, a prehistoric civilization that prospered in Sardinia between the 18th and 15th centuries BC and which is famous for the construction of Nuraghi, megalithic towers typical of the island of which more than 7 thousand have been built throughout Sardinia.
If you are interested in Sardinian ancient history then do check out this list of archaeological sites in around Sardinia. https://www.nurnet.net/mediateca/