57km (35 miles) NW of Palermo.
The lone volcanic island of Ustica is known as "The Black Pearl," dramatically surging as it does out of the cobalt sea surrounding it.
Initially inhabited by the Phoenicians, the Greeks followed, naming the island Osteodes ("ossuary"), in memory of the skeletons of 6,000 Carthaginians who were brought here and abandoned without food or water.
Attempts to colonize it in the Middle Ages failed because of raids by Barbary pirates. The Bourbons repopulated it in 1762 with people from the Aeolian Islands and Naples. They constructed a trio of towers to defend the island against pirates.
As late as the 1950s, Ustica was a penal colony, a sort of Alcatraz of Sicily. Antonio Gramsci, the theorist of the Italian Communist Party, was once imprisoned here. And, in one of the most secret meetings of World War II, British and Italian officers met here in September 1943 to discuss a switch in sides from Mussolini to the Allies.
Ustica is tiny, only 8.6 sq km (3 1/3 sq miles), with a population of roughly 1,370, yet it is the oldest island in the Sicilian outer archipelago -- even older than the Aeolian Islands. Because its jagged coastline is riddled with creeks, bays, and caves, Ustica is best explored by a rented boat circling the island.
In 1987, Sicily designated part of the island a national marine park, and today its clear waters, filled with aquatic flora and fauna and archaeological trails, attract sea lovers from around the world.