Geologically the Burren consists of a sequence of massively bedded Carboniferous limestones, dipping gently to the south. Individual rock layers form pavements of limestone which give a terraced effect where the hills slope eastwards to the adjoining lowlands. The landforms owe much to glacial erosion during the Quaternary ice ages, as well as to the effects of limestone dissolution.
Drainage is almost entirely underground and there are well developed cave systems.
From a botanical point of view the Burren is one of the most fascinating regions of Western Europe. Many of the plants found in the Burren occur nowhere else in Ireland and the combination of plants usually found in Arctic regions or on high mountains with other species from southern Europe is remarkable. Late May and early June is the best time to see the flora of the Burren in full glory. The fauna is less spectacular but also interesting. There are also many Pine Martens in the Burren, a few of which have been translocated to Killarney National Park in the past.