Derryvree’s Intertill Fen
Archived: 18 September 2026
At approximately 31,235 BCE, Ireland lay within a variable Late Pleistocene glacial interval. At Derryvree, County Fermanagh, freshwater sediments and organic remains between two tills show that ice temporarily retreated or ceased occupying the locality. Fossils indicate cold, wetland tundra with low vegetation, aquatic plants and insects. Elsewhere, especially Castlepook Cave, animal remains demonstrate intermittent habitats for reindeer, giant deer, mammoths and predators. A possibly tool-marked reindeer bone suggests an early human visit, but securely dated settlement remains unproven. The date is a modern calibrated marker, not a year-specific event; evidence reveals shifting ice, water, ecosystems and uncertain human presence.