Santorini is the largest island of a small, circular archipelago of the same name. It is also the remnant of a volcanic caldera that appeared about 3,600 years ago, in the wake of one of the biggest volcanic eruptions in recorded history -- the Minoan eruption.
According to a popular theory, it is the source of the legend of Atlantis. It may also have led to the indirect collapse of the Minoan civilization in Crete, through a gigantic tsunami.
The municipality of Santorini includes the inhabited islands of Santorini and Therasia and the uninhabited islands of Nea Kameni, Palaia Kameni, Aspronisi, and Christiana.