The Castlepook reindeer femur is especially intriguing because it may indicate Upper Palaeolithic carcass processing while remaining insufficient evidence for settlement or continuous occupation. Combined with faunal deposits accumulated across millennia, it encourages a view of Ice Age Ireland as intermittently accessible and ecologically dynamic rather than empty or understood. The article also highlights how changing coasts, ice margins and poor preservation complicate efforts to trace human movement. How should researchers weigh the marked bone alongside the wider faunal record and north-west European comparisons when considering whether early visitors merely passed through Ireland or returned repeatedly during favourable climatic phases?