The vast lake system of Lough Erne in County Fermanagh takes its name from a mythical woman named Erne, described in some sources as a lady-in-waiting to Queen Méabh at the royal court of Cruachan. According to the legend, Erne and her maidens were terrified when a fearsome giant emerged from Oweynagat, the infamous Cave of the Cats — an otherworld entrance associated with Samhain and the supernatural.
The story
The women fled northward through Ulster in blind panic, but they were overtaken by the waters. Erne and her companions drowned in the river, and their bodies dissolved to form the great lake that now bears her name. This motif of a goddess or noblewoman drowning to create a body of water is widespread in Irish mythology, symbolising the transformation of divine power into the life-giving landscape.
Scholars including T.F. O'Rahilly have suggested that the name Lough Erne ultimately derives from the Érainn, an ancient Irish population group who may themselves have been named after a goddess called Érann. The Dindshenchas, the medieval Irish lore of place-names, preserves multiple origin stories for the lake, but the drowning of Erne fleeing the giant of Oweynagat remains the most widely told.