BIRM-166’s Open Water
Archived: 4 October 2026
Around 30,289 BCE, Ireland cannot be described through a specific recoverable year, but through a broad Late Pleistocene interval. At Derryvree, County Fermanagh, freshwater organic deposits between glacial tills, dated broadly to the middle-to-late 30,000s calibrated years BP, record a temporary ice-free wetland. Plant and insect remains indicate cold, open, treeless terrain with pools, sedges, mosses and tundra vegetation, later overridden by ice. Castlepook Cave preserves a mixed, long-term assemblage of cold-stage mammals, including mammoth and reindeer. A possibly cut-marked reindeer bone may indicate a brief human visit, but no evidence demonstrates permanent settlement, society or continuity within Ireland itself.