Area marina protetta Penisola del Sinis - Isola Mal di Ventre, Marine protected area in Province of Oristano, Italy.

The Area marina protetta Penisola del Sinis - Isola Mal di Ventre is a marine protected zone in the Province of Oristano spanning about 25,673 hectares. The region contains sandy beaches, rocky shorelines, and shallow water areas that support diverse marine life.

The marine reserve was established by a Ministry of the Environment decree of 12 December 1997, published in the Gazzetta Ufficiale no. 45 of 24 February 1998. A corrective ministerial decree followed on 17 July 2003, and on 20 July 2011 a further decree, published in the Gazzetta Ufficiale no. 266 of 15 November 2011, redrew its boundaries, zoning and activity rules after the municipality of Cabras requested a new perimeter on 8 November 2004.

On the south shore of the Cabras lagoon lies Cuccuru Is Arrius, a pre-Nuragic site dated 4500–1800 BC, where tombs held figurines linked to the cult of the bull god and the mother goddess. Nuragic sites are scattered across the Sinis peninsula. The Phoenicians founded Tharros, later held by Carthaginians and Romans.

The area is divided into three protection zones, each with different regulations for access and activities. Visitors should check the specific rules for each zone before visiting to understand what is permitted in the area they plan to explore.

The waters contain extensive meadows of seagrass that provide shelter for Mediterranean lobsters, moray eels, and barracudas in their natural habitat. This underwater vegetation plays a key role in maintaining water quality and attracts diverse fish populations.