Around 1600 BC, the island, which was probably named Strongili at that time, was sunk due to a strong volcanic eruption. The volcanic explosion was so violent that it resulted in one of the world's largest calderas with a diameter of 10 km (6,2 mi). Only side fragments of the previous island remained.
The caldera is a huge depression in the top part of the volcano, resulting from a violent eruption destroying the upper part of the volcanic cone.
