Benglenisky is a 516-metre mountain in Connemara, County Galway, on the western edge of the Twelve Bens within Connemara National Park. The second southernmost summit in the range and the lowest of its core peaks, it stands slightly apart from the main central ridge, linked by a high north-easterly ridge to Bengower and also connected with Benlettery. Its Irish names refer either to a water-filled glen on its south-eastern side or to a “Black Peak” on its north-western side. That north-western flank was associated with green Connemara marble quarrying begun by Thomas Barnwall Martin in the 1820s. Though relatively accessible to walkers, its position outside the main celebrated ridge routes has given it a quieter reputation.