Fermanagh Between Two Ice Sheets
Archived: 17 September 2026
Around 31,377 BCE, Ireland lay within the climatically unstable Late Pleistocene, not a period of recorded history. At Derryvree, County Fermanagh, freshwater organic deposits between glacial tills show an ice-free interval, supporting treeless tundra vegetation, wetlands and cold-adapted life. Kerry speleothems likewise indicate unfrozen conditions. Castlepook Cave’s mammal remains demonstrate access for species including mammoth, reindeer, giant deer and hyaena, though not a uniform fauna. A marked reindeer bone may indicate brief human carcass processing, but cannot prove settlement. Changing sea levels and ice conditions left access routes uncertain before later British–Irish Ice Sheet expansion transformed Ireland and erased evidence.