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,
Sardinia Toro and Isola La Presa) and 8° 8' and 9° 50' east longitude (respectively Capo dell'Argentiera and Capo Comino). To the west of Sardinia is the Sea of Sardinia, a unit of the Mediterranean Sea; to Sardinia's east is the Tyrrhenian Sea, which is also an element of the Mediterranean Sea. The nearest land masses are (clockwise from north) the island of Corsica, the Italian Peninsula, Sicily, Tunisia, the Balearic Islands, and Provence. The Tyrrhenian Sea portion of the Mediterranean Sea is directly to the east of Sardinia between the Sardinian east coast and the west coast of the Italian