600 million years ago (mya), Ireland as we know it today did not exist and where we stand today in Kerry Geopark was an ocean (the Proto-Atlantic) with large land masses to the north and to the south. Over time these two land masses moved towards each other, crumpling up the sea floor between them. They crashed together about 500 mya and continued to push against each other. Caught in this vice the rocks between and at the edges of the two land masses were crumpled, crushed and folded against each other. This intense crumpling pushed the rocks up into a mountain range known as the Calendonide, to the north of where South-West Kerry is located today. The rocks which made up this mountain range consisted of marine sediments originally laid down in horizontal layers on the sea floor between the two land masses. As they were raised up and crumpled and crushed, the layers were contorted into various shapes and sometimes sheared and cut.