The IMC was founded in 1942 by Bill Perrott and a group of other climbers in south Dublin, within easy reach of Dalkey Quarry. They established several climbs in Dalkey and at other locations around Dublin such as The Scalp, Bray Head, and Ireland's Eye; these were the first steps in the development of climbing in Ireland. This group, now known as The Old IMC, disbanded in 1944.