Derryvree’s freshwater deposits show that cold, treeless wetlands could offer seasonal productivity between glacial incursions, while Castlepook’s mixed cave fauna warns against treating all animal remains as one community or moment. The possible cut mark on a reindeer femur deepens this uncertainty: it may signal human carcass processing without demonstrating settlement. Together, these records suggest that habitable landscapes need not have supported permanent occupation. How might further dating, spatial analysis, and comparison with north-west European sites help distinguish brief human visits from repeated seasonal use of Ireland’s unstable Late Pleistocene wetlands and open grazing grounds during rapidly changing regional climates?