South of Sant’Antioco a few uninhabited volcanic islets and rocks can be seen, the nearest being Vacca as well as the nearby Vitello rock. The only vegetation that manages to thrive here is not trees, but a few lentisco shrubs. By way of compensation, the flora is very interesting, including a strange crystalline grass. The fauna is characterised by insects, frogs and unusual isopods. Because of its position the Vacca is an important resting and nesting place for many birds, such as seagulls, jays, southern crested cormorants and
Regina hawks. A short distance from Vacca is Vitello, a craggy rock connected to the motherland by an undersea reef. Further from Capo Sperone is the Island of Toro, a craggy rock where particular botanical species grow in extreme conditions. There is also an abundance of migratory marine birds, two of which are the splendid, large birds of prey, the rare falcon and the Regina hawk.