Oristano’s principal museum has one of the island’s major archaeological collections, with prehistoric artefacts from the Sinis Peninsula and finds from Carthaginian and Roman Tharros. There's also a small collection of retabli (painted altarpieces), including the 16th-century Retablo del Santo Cristo, from the workshop of Pietro Cavaro. It depicts a group of apparently beatific saints, but look closer and you’ll see they all sport the instruments of their torture slicing through their heads, necks and hearts.

　　The permanent collection, which includes a scale model of 4th-century Tharros, is displayed on the upper floor. Here you'll find prehistoric obsidian and flint spearheads, axes, bones and a smattering of jewellery from the Sinis Peninsula. More interesting, though, is the stash of finds from Tharros, which includes ceramics, glassware, oil lamps, amphorae and a range of pots, plates and cups.