Ustica is a small Italian island in the Tyrrhenian Sea. It is about 5 kilometres across and is situated 52 kilometres north of Capo Gallo, …Ustica is a small Italian island in the Tyrrhenian Sea. It is about 5 kilometres across and is situated 52 kilometres north of Capo Gallo, Sicily. Roughly 1,300 people live in the comune of the same name. There is a regular ferry service from the island to Palermo in Sicily.