Sardinia world (22 centenarians/100,000 inhabitants). Sardinia is the first discovered Blue Zone, a demographic and/or geographic area in the world with an oversize concentration of centenarians and supercentenarians. In 2016 there were 50,346 foreign national residents, forming 3% of the total Sardinian population. The most represented nationalities were: Sardinia's most populated cities are Cagliari and Sassari. The Metropolitan City of Cagliari has 431,302 inhabitants, or about ¼ of the population of the entire island. Eurostat has identified in Sardinia two Functional Urban Areas: Cagliari, with 477,000 inhabitants, and Sassari, with 222,000 inhabitants. Sardinia is one of the five Italian autonomous regions,
History of Sardinia the Abealzu-Filigosa and Monte Claro culture of the Chalcolithic period, developed in the island contemporaneously with the appearance of the megalithic phenomenon. The dolmens culture, around the end of the 3rd millennium BC, passed with other typical material aspects of Western Europe (e.g. Bell Beaker) through by the Sardinian coast even in Sicily. Prehistoric and Pre-nuragic monuments and constructions that characterise the Sardinian landscapes are the Domus de Janas (), the menhir and Statue menhir and the dolmens. Archeological cultures of Sardinia in the pre-Nuragic period: Bronze Age Sardinia is characterised by stone structures called nuraghes, of which there are