The cave is one of Ireland's largest natural caves, running for around 402 metres to a depth of 46 metres...The earliest historical reference to the cave is in the Trecheng Breth Féne "A Triad of Judgments of the Irish", more widely known as "The Triads of Ireland". The Triads are a series of manuscripts that date from the 14th to the 19th century AD, describing Dunmore Cave (written as "Dearc Fearna") as one of "the three darkest places in Ireland".This may be in reference to events in the "Annals of the Four Masters", a chronicle of medieval Irish history compiled...