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 the pre-Roman noun *"s(a)rd-", later romanised as ' (feminine '). It makes its first appearance on the Nora Stone, where the word "Šrdn" testifies to the name's existence when the Phoenician merchants first arrived. According to "Timaeus", one of Plato's dialogues, Sardinia (referred to by most ancient Greek authors as "Sardò", Σαρδὼ) and its people as well might have been named after a legendary woman going by Sardò (), born in Sardis ("Σάρδεις"), capital of the ancient Kingdom of Lydia. There has also been speculation that identifies the ancient Nuragic Sards with the Sherden, one of the Sea Peoples. It