Among the largest volcanic structures of Lesvos is the volcanic caldera of Vatoussa with a diameter exceeding 8.5 kilometers. The term caldera or caldera comes from the Spanish (caldera: cauldron) and describes the depression of the relief formed by the collapse of the volcanic cone of a volcano or the erosion of the walls of the volcanic crater.
The Vatoussa volcano is associated with the main volcanic activity of Lesvos that took place between 18.5 and 17 million years ago. Successive volcanic eruptions formed the extensive caldera and caused the collapse of the western side of the volcanic cone.The hills that surround Vatoussa today form the limits of the caldera.
After its formation, subsequent magma eruption, formed small volcanic structures, which we observe today between Vatoussa and Khidera.
The hydrothermal activity that followed the volcanic activity caused the rocks inside the caldera to disintegrate.In the long period of time that has passed since the volcano was active, there have been intense tectonic movements, erosion and destruction of the rocks so that its original form is not easily discernible. However, observing the area carefully one can perceive the shape of the large elliptical caldera. Vegetation rages inside the basin due to the rich soil created by the disintegration of the volcanic rocks.
