Santorini is landlocked.
Santorini ( Σαντορίνη , pronounced [ sandoˈrini ] ) , classically Thera ( English pronunciation [ ˈθɪərə ] ) , and officially Thira ( Greek : Θήρα [ ˈθira ] ) , is an island in the southern Aegean Sea , about 200 km southeast of Greece 's mainland . It is the largest island of a small , circular archipelago which bears the same name and is the remnant of a volcanic caldera . The municipality of Santorini includes the inhabited islands of Santorini and Therasia and the uninhabited islands of Nea Kameni , Palaia Kameni , Aspronisi , and Christiana .