The island of 57 km2, 9 km long and 3 km wide. The climate, as well as the vegetation are extremely Mediterranean. The average temperature in January is 7.80C, and in July 28.30C, and the average temperature of the sea is 22-250C. The average yearly precipitation is 850mm, and happens mostly during autumn and winter. There are four ports and 24 bays on the island, and was civilised from the Illyric times.

In Roman times it acquires the role of the stationary-crossroads of the naval routes, of protecting and supplying of the coastal towns, and, above all, of the safe exile. There are over 200 archaeological finds, beginning from the earlier Stone age (Roman sarcophaguses, mosaics, early Catholic buildings, fortified country houses