It is a small marine area (less than 100 hectares) located in the northwest of Ibiza, on the coast between Cap Negret and Punta des Castellar, where we find the small archipelago of Ses Margalides. The presence of the Priority Habitat of Community Interest, Posidonia oceanica meadows, underpins the quality and importance of this area. The species present in this area include Eleonora’s Falcon (Falco eleonorae) and the European Shag (Gulosus aristotelis). Bottlenose Dolphins (Tursiops truncatus) and Loggerhead Turtles (Caretta caretta) can also be seen in this area. It is also worth mentioning the presence of Euphorbia margalidiana on the large islet of Ses Margalides. This species is endemic to the island. Uncontrolled anchoring and excessive maritime traffic are the main threats to this area.