All along the Galician coast are various archipelagos near the mouths of the rías. These archipelagos provide protected deepwater harbors and also provide habitat for seagoing birds. A 2007 inventory estimates that the Galician coast has 316 archipelagos, islets, and freestanding rocks. Among the most important of these are the archipelagos of Cíes, Ons, and Sálvora. Together with Cortegada Island, these make up the Atlantic Islands of Galicia National Park. Other significant islands are Islas Malveiras, Islas Sisargas, and, the largest and holding the largest population, Arousa Island.