Santorini is an island in the Aegean, known to the Greeks as Thera. It is the southernmost of the Cyclades, 70 miles northeast of Crete. Santorini is shaped like a crescent, the horns pointing west; between them lies the island of Therasia. The space so enclosed, 18 miles in circuit, is an enormous, sea-filled volcanic crater, and the three small islands within it (the Kaumenes) are all of volcanic origin.
Santorini and Therasia have lofty and precipitous shores (up to 1,000 feet) next to the crater; on their outer sides they slope away gradually to the sea, except that in the southeast of the former Mount St Elias rises to 1,887 feet. The chief town, Fira (an alternative pronunciation of "Thera"), on the west coast of Santorini, is built on the cliffs of tufa and perched some 900 feet above the water's edge. Excellent wine is grown in the disintegrated volcanic soil. Eruptions have taken place, chiefly near the Kaumenes, in the years 196 BC, 726 AD, 1573, 1650, 1707, and 1866.