More or less elaborate 11th- or 12th-century narratives have survived around Galway Bay, Lough Neagh and Lough Ree, which seem to be related to similar (though less ancient) stories in Wales (Cantre'r Gwaelod, Llys Helig, Bala Lake, Llynclys), Cornwall (Lyonesse), Brittany (Ys) and Normandy (Forêt de Scissy).
The poems of the lake-burst of Lough Erne and the eruption of Brí (where the legendary character Midir lived) have been lost.
In Wales the flood myth is elaborated in the story of Dwyfan and Dwyfach, who saved people and animals from the great deluge caused by the monster Avanc living in Llyn Llion (possibly Bala Lake).
Its Irish counterpart as told in the Lebor Gabála Érenn only links up with the Biblical story of Noah's flood.
[citation needed] The cave of St Patrick's Purgatory on Station Island in Lough Derg (Ulster), moreover, was identified in the Tractatus de Purgatorio Sancti Patricii as the entrance to the Underworld.