Along the western Istrian coast there are several island groups among which the most interesting, the largest and most indented is the Brijuni island group with its 14 islands and islets covering and area of 7.51 km2.
The National Park of Brijuni includes the following islands: Veliki Brijun, Mali Brijun, St. Mark, Gaz, Okrugljak, Supin, Supinić, Galija, Grunj, Vanga (Krasnica), Pusti (Madona), Vrsar, St. Jerome and Kozada. (Krasnica), Pusti (Madona), Vrsar, Sv.Jerolim i Kozada.
The islands are made of horizontal or slightly inclined layers of limestone from the Cretaceous, on which in places there are layers of carbonated brown or red soil. The stone that belongs to that formation is white in colour, easily breakable, of marble structure and is abundant in clay and flint.
The main characteristic of the Brijuni archipelago is the extraordinary biological diversity given thanks to its geographical location, its geological base and geomorphology, its diversity of the habitat and its island isolation.
It is important to underline that the sea forms 80% of the protected area of the National Park and has almost all the elements of the marine eco-system of the Adriatic.
The archipelago of Brijuni is an extraordinary blend of natural, historical and cultural heritage. The mild climate and the favourable geographical conditions, deep retracted bays and easily defendable elevated fortifications, have secured a continuum in the human activity on the island from a pre-historic age until the present day.