Slieve Bloom Mountains

The Slieve Bloom Mountains Nature Reserve is Ireland's largest state-owned nature reserve, encompassing over 2,300 hectares of mountain blanket bog straddling the border between Counties Laois and Offaly in the heart of Ireland's midlands. These ancient mountains, despite their modest current height of 527 meters at Arderin summit, represent one of Europe's oldest mountain ranges—once towering to 3,700 meters before 450 million years of erosion shaped their present gentle profiles. The reserve holds multiple conservation designations including Special Area of Conservation, Special Protection Area for hen harriers, Ramsar Wetland Site, and Council of Europe Biogenetic Reserve, reflecting its international significance for protecting globally rare mountain blanket bog habitat.