Mountain Avens at Derryvree
Archived: 2 October 2026
About 30,342 BCE, Ireland lay within the climatically unstable Marine Isotope Stage 3, rather than any recordable historical year. Derryvree, County Fermanagh, preserves freshwater silts between glacial tills, indicating an ice-free interval with cold, open tundra wetlands supporting mountain avens, bogbean and aquatic plants. Cave deposits at Castlepook, County Cork, document mammoth, reindeer, giant deer and predators, although their chronology and associations remain imperfect. A cut-marked reindeer femur may indicate human butchery around 31,000 BCE, but cannot demonstrate settlement. As ice expanded towards the Last Glacial Maximum, environmental evidence is reliable, whereas political, cultural and religious history remains wholly unknown.