|Image: geologic map showing limestone areas in Ireland.|
Ireland has a rather complicated geoloy, as the island is the remains of ancient mountain ridges, formed during orogenies (orogeny=forming of mountains) very long ago. The rocks are generally very well folded, and metamorphic and crystalline rocks are common. The flat central of Ireland is not suitable for caves, the rocks are deep below the surface and the ground water table. But caves can be found in small patches of limestone and marble in the mountain ridges along the coasts.
Limestone areas, suitable for karst development, are rather small and irregular. The limestones are often metamorphic, which means marble. There are three main karst areas:
Additionally there are several very small areas in County Kerry and County Kilkenny.