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 is suggested that the name had a religious connotation from its use also as the adjective for the ancient Sardinian mythological hero-god Sardus Pater ("Sardinian Father" or "Father of the Sardinians"), as well as being the stem of the adjective "sardonic". In Classical antiquity, Sardinia was called a number of names besides "Sardò" () or "Sardinia", like (the Latinised form of ), "Sandaliotis" () and "Argirofleps" (). Sardinia is the second-largest island in the Mediterranean Sea (after Sicily and before Cyprus), with an area of . It is situated between 38° 51' and 41° 18' latitude north (respectively Isola del