The sea and the coastal environments included in the protected area are extremely heterogeneous, with naturalistic and archaeological elements of considerable value. The conformation of the coast is in some stretches low and sandy, in others rocky with small reefs or with imposing cliff formations. From Su Siccu, the end of the protected area in the Gulf of Oristano, the landscape is characterized by the lagoon, with a sandy tongue separating the pond of Mistras from Mare Morto; with the promontory of Capo San Marco the coast becomes rocky and then descends into the Mare Vivo, in San Giovanni di Sinis, and reascends with the cliff walls of Torr'e Seu. Towards the north the coast is characterized by low reefs and long quartziferous sandy shores of considerable beauty, like Is Arutas and Mari Ermi, with stretches of dunes towards the hinterland covered by a typical Mediterranean vegetation. When you pass the Capo Sa Sturaggia, the high and white cliffs of Su Tingiosu close the coastal territory of the protected area. In the clear sea there are two uncontaminated islands: the granite Isola Mal di Ventre and the basaltic Scoglio del Catalano.