At the northern coast of Methana peninsula there are some huge crater structures of steam explosions that took place thousands of years ago. Uprising magma was heating up the ground water horizon and caused sudden steam explosions. While these explosions happened, rare rocks were delivered from deeper parts of the earth. So you may find the rocks of the oldest (submarine) eruptions in the area of Methana and some limestones and ophiolites. All the area around was cracked into small rocks and landslides are common from the surrounding volcanoes.
Today it is one of the most beautiful landscapes of Methana. You may discover this area by using the old hiking path that starts near "Palia Loutra" / Kato Mouska and leads you to the historic lava dome of Kameni Chora.