The Eresos volcanic dome is the great hill of Prophet Ilias that dominates the south of the settlement.
It is a typical volcanic building that belongs to a series of volcanic buildings that appear in the wider area and were formed in the last phase of volcanic activity, 16.5 million years ago.
Their creation is associated with magma rise that moved at a low speed, penetrated and raised to the surface the older metamorphic rocks of the background, which today appear placed on the newer volcanic rocks along the provincial road of Antissa – Eresou.Today, the church of Prophet Ilias is built on top of the hill.In the wider area the intense erosion of the surface rocks and the tectonic activity reveals a structure that probably constitutes a large magma chamber.
The structure, called laccolith, was created by magma intrusion into the pre-existing rocks, expands horizontally and obscures them, resulting in a flat base and mushroom-shaped top.
