Roman bridges occupy a position of primary interest in the viability of Roman Sardinia. These are works of art from the road network whose belonging to Roman architecture is easily comparable with those of other provinces, despite the alterations that have taken place over the centuries. The Roman bridge of Sant’Antioco, now heavily remodeled in its structure, is unique for its position on the territory. Unlike the other bridges of Roman Sardinia, it connects the mainland to an island and not the ford of rivers or differences in height, it is an integral part of the Roman road Karalibus Sulcos, which starting from Sulci, caput viae as the milestones attest, crosses the Cixerri Valley. to get to the city of Karales, thus avoiding to cross the more tortuous coastal road the Tibulas-Sulcis. Of its importance, and of the need for restoration, we have news a few years after the repopulation of the island. In fact, the Turin State Archives retains a file containing the "CALCULATION formed by the Ro Measurer Viana of the most necessary expenditure to make the ancient bridge trafficable, which connects the Island of St Antioco with the Littorale del Regno", dated 17 July 1774. Today, after the restorations of 1858, 1893 and 1920, the bridge is located on a lawn, the result of a filling carried out around 1940 to allow military vehicles to easily reach the quay or the transport of goods by wheeled vehicles for the Sardinian continent, without going through the Roman bridge. In 2006, a restoration project made it possible to preserve the monument which risked irreversible degradation especially of its more delicate parts such as the sandstone vaults and the parapets, the latter no longer original perhaps from the early Middle Ages.