The nuragic complex of Su Mulinu stands in close proximity to the modern town of Villanovafranca. The fortress, built with limestone and sandstone boulders, documents the presence of different construction techniques and phases leading to the creation of the present three-lobed bastion and the antemural wall with towers and curtains equipped with loopholes. The archaeological excavation, which is still ongoing, also revealed an exceptional temple function of the monument, evidenced by the discovery of an extraordinary altar-vessel molded in the form of a nuraghe. For the altar, made of tuffaceous sandstone by superimposing three distinct elements, a date to the 9th-7th centuries BC is proposed.
The use of the nuraghe and the vast surrounding settlement likely began from the middle of the 2nd millennium B.C. (16th-15th centuries B.C.), persisting, with ups and downs, until the High Judicial Age (11th century B.C.).