The mountain range of Erymanthos is the highest one of an extended mountainous area in north-west Peloponnese, consisting of several peaks and characterized by a multivarious relief with many springs, valleys, plateaus and gorges. From the springs of Olenos summit(2221m) two small rivers are formed, crossing the two biggest gorges of Erymanthos. These gorges are very impressive with several spectacular waterfalls. The geological substrate is composed of plate limestone with layers of ceratolith and flysch. The northern slopes have Abies cephalonica forests, the south slopes are covered with Abies cephalonica and Juniperus foetidissima. The western slopes have extended calcareous cliffs.