Insular Italy

Insular Italy ( or just ) is one of the five official statistical regions of Italy used by the National Institute of Statistics (ISTAT), a NUTS1 level region.
Insular Italy is defined only for statistical and for some elections and includes the two main Italian islands: Sicily and Sardinia, together with other small islands and archipelagos next to them.
Geography.
Sicily is the largest Mediterranean island with an area of . To the east, it is separated from the Italian mainland by the Strait of Messina, about wide in the north, and about wide in the southern part. Its highest point is Mount Etna (), the largest active volcano in Europe with an altitude of . The longest river of the island is the Salso river, long.
Sardinia is the second largest Mediterranean island with an area of . To the east is the Tyrrhenian Sea that separates the island from mainland Italy, and to the north is the Strait of Bonifacio that separates Sardinia from the French island of Corsica. Its highest point is Punta La Marmora () with an altitude of . The longest river of the island is the Tirso river, long.
Regions.
Insular Italy has 2 of the 20 regions of Italy, including 24 provinces and 1,789 comuniː
The "comuni" with more than 100,000 persons living in them areː