Tomba dei giganti di Osono, Bronze Age passage grave in Triei, Italy.

The Tomba dei Giganti di Osono is a Bronze Age collective tomb near Triei, over 22.5 m long. Its 10 m chamber, roof and arched inner walls are the oldest parts and remain intact. The 19 m exedra was added later, and the central portal stele was replaced by a trilithon of two low blocks topped by a massive lintel.

The tomb began as a burial site during the early Bronze Age and remained in use for approximately 600 years, showing its lasting importance to the Nuragic people. Later modifications to the structure reveal how burial practices changed and adapted over this long period.

The name "Tumbas de sos zigantes" in Sardu and "Tombe dei Giganti" in Italian refers to these collective tombs. At Osono, the later entrance replaced the central portal stele with a trilithon: two low blocks topped by a massive lintel, a form not found elsewhere on the island.

The tomb lies in open countryside at Osono, near Triei, and is reached on foot over unpaved, uneven ground; sturdy shoes are advisable. The 10 m chamber is intact and can be entered, while the 19 m exedra stands in the open with no shelter, so bring water and sun protection in summer. There are no visitor facilities on site.

The tomb shows signs of reconstruction in different periods, with an additional stone structure added that came from a much later age. These layers in the construction show that the site remained important to people long after it was first built.