Castlepook and the Growing Ice
Archived: 26 September 2026
Around 30,633 BCE, Ireland lay within the climatically unstable Marine Isotope Stage 3, as the British–Irish Ice Sheet expanded unevenly before the Last Glacial Maximum. No evidence permits annual precision or a uniform description of conditions. Glacial erosion, changing sea levels and shifting ice created variable habitats. Castlepook Cave preserves remains of mammoth, reindeer, giant deer, predators and cold-adapted mammals, indicating intermittent food webs, while Derryvree records treeless wetlands between glacial advances. A possibly cut-marked reindeer bone suggests, but does not prove, brief Upper Palaeolithic human activity. No evidence supports settled communities, politics or culture. Environmental change defines this period.