Mt. Ainos is α short mountain range comprising the main land mass of Cephalonia. It is located at the southeast ρart οf the island in α northwest-southeast direction. The ρart οf its crest exceeding the 1000 m. altitude has α length of 11 km. Its highest peak is Megas Soros (1628 m) followed by Stavros (1532 m) Kroukoubias (1508 m) Vounos (1312 m) Vigla (1050 m) and Kefali Petri (1025 m). During the Mesozoic Era, about 225 million years ago, mountain area was covered by the waters of the Tethys Sea, which covered all of Greece, comprising the Alpine Geosyncline. Tethys Sea, thousands of kilometers long, 1500 km wide and parallel to the Equator, was located between the two great continents of that era, Laurasia to the north and Gondwana to the south. Ιn the depths of Tethys, sediments were continually accumulating, washed out from the rocks οf Laurasia and Gondwana. Numerous organisms in great numbers lived in its waters. Their shells and skeletons were buried in the sediments and fossilized. By the end of the Mesozoic Era (about 65 million years ago) α period of intensive earth crust movements began influencing the whole Tethys region. All these tectonic movements, which still continue today, resulted in the formation of the contemporary Hellenic landscape. The emergence of the mountainous mass of Ainos developed gradually as α result of the above tectonic movements. Ainos consists mostly of Cretaceous limestone and dolomites which belong to the Paxos (or Preapulίan) Geotectonic Zone. They appear in thin to thick bedded formations and contain fossils of Bryozoa, Sponges, Molluscs and Echinodermata.