The local limestone formed during the Carboniferous Period when Ireland was at the equator, and warm, tropical water habitats dominated. Weathering of these rocks over the past 10,000 years has created a unique landscape. Some of these features, such as ‘boulders in their sockets’, are thought to be globally unique to the Lough Mask region. ‘Eggbox pitting’ is another common weathering texture seen in the region. The limestone pavement can be seen on the walking trail through Clonbur Woods and contains many fossil evidence of the biodiversity of the past.

The Clonbur woods constituted the largest demonstration site for the “Woodland restoration in Ireland” project, an awarded EU-LIFE Nature 4-year project (2006 to 2009) co-funded by Coillte that saw almost 300ha undergo restoration work. Native woodland is a relatively uncommon habitat in Ireland, having been cleared by millenia of human activity. It is a very important habitat for wildlife as it supports many bird species, mammals, such as the pine marten and red squirrel, invertebrates and a wide diversity of plant species.