The height of the Santorini Caldera is 150 to 350 meters. The length of the island from cape Exomitis to cape Mavropetra is 18 kilometers. Santorini’s width varies from 2 to 6 kilometers.
The largest island is Thira with the main town of Thira / Fira.
The second largest (part of the caldera rim to the west) is Thirasia with the town of Manolas. In the center of the Caldera are the basaltic volcano cones of Nea Kameni (new eruption), and southwest of that, the older cone called Palea Kameni (ancient eruption).
The smallest island is Aspronisi (White Island), also a part of the caldera wall. Eleven eruptions since 197 bc have made the five islands.