Derryvree’s Freshwater Window
Archived: 10 September 2026
About 31,843 BCE, Ireland lay within the climatically unstable Late Pleistocene, before the last British–Irish Ice Sheet reached its maximum. Freshwater sediments at Derryvree, County Fermanagh, dated broadly to this period, preserve evidence of ice-free wet tundra, mosses, sedges and herbaceous vegetation between glacial advances. Cave records and faunal collections indicate fluctuating milder phases and varied mammals, including reindeer, mammoth and hyaena, although deposits cannot reconstruct single communities. Possible cut marks on a Castlepook reindeer bone suggest a human visit, not settlement. Subsequent ice expansion destroyed or buried much evidence, leaving fragmentary environmental archives rather than a documented human society.