Derryvree’s sediments preserve a local environmental window between glacial advances, but they cannot represent all Ireland at 30,169 BCE. Juniper, sedges, mosses and freshwater plants suggest a tundra wetland, whereas Castlepook’s fauna reveals connections with north-west Europe. Together, these records indicate ecological richness, mobility and climatic instability, rather than a uniformly frozen island. The possible tool mark on a reindeer bone complicates the picture, because it may reflect a brief human visit without demonstrating settlement. How should interpretations of Derryvree’s local landscape and Castlepook’s complex cave remains shape future investigations of any possible seasonal human activity there in late-MIS-3 Ireland?