The Tuvixeddu necropolis occupies a limestone hill west of the city centre and contains the largest concentration of Phoenician-Punic rock-cut tombs in the Mediterranean world. The tombs — square-cut shafts descending into burial chambers, some with carved facades — date mainly from the 7th to 2nd centuries BCE, when Cagliari (then Karalis) was a major Carthaginian port. The scale is extraordinary: the hillside is honeycombed with tombs stretching across several hectares.
Access has been improved in recent years as part of a public park development, and some of the better-preserved tomb interiors can be entered with a guide. The site also preserves some of the Punic city's original topography — the views from the hilltop over the modern city give a sense of how the Phoenicians positioned their settlement in relation to the harbour and the hinterland.