Torre di Carcangiolas, Historic coastal tower in Quartu Sant'Elena, Italy.

Torre di Carcangiolas is a ruined coastal tower of truncated-cone shape, built from limestone and granite, standing a short distance from the waterline on the beach at Quartu Sant'Elena. Its collapsed remains lie partly toppled into the sea.

The tower is mentioned by the historian Giovanni Francesco Fara, who died in 1591, so it was built before that year. It was reused as a lookout post during World War II. On 23 December 1979 at 7 pm a violent storm surge brought down part of the structure, and its recovery is still debated.

The tower is named after the nearby locality of Carcangiolas and is recorded by the historian Giovanni Francesco Fara, who died in 1591. During World War II the site was reused as a lookout post. On clear days, four towers can be seen to the west (Mezza Spiaggia, Poetto, Sant'Elia) and Cala Regina to the east.

The structure sits right at the water line and is harder to reach during high tide than at low tide. It helps to scout the area before visiting to find the best time and safest route to the tower.

Portions of the structure were torn away from the foundation by the force of the sea and now rest on the seabed. This damage allows visitors to see parts of the tower that would normally be hidden, revealing how nature eventually overpowers human construction.