The inner part of a monogenetic volcano has a vertical passage of lava. In case of a young active volcano, lava periodically gushes out from its crater on top by way of a vertical passage.
But like a human, a volcano also becomes old. The sharp conical hill in the picture is an extinct volcano that used to be active a long time ago. The eruptions that once entirely covered this hill have been encroached and finally the giant rock made from cold lava in the vertical passage appears as a form of the sharp conical hill. Hence this hill, 190 meters high, is made up of just one huge rock that has originated from lava.
Licensed tour guide, travel consultant,
Masahisa Takaki.
全国通訳案内士 高木聖久。
