Corpus of Electronic Texts Edition
Cath Maige Tuired: The Second Battle of Mag Tuired (Author: [unknown])

section 79

Then he asked the cupbearer what power he wielded. He answered that he would bring the twelve chief lochs of Ireland into the presence of the Fomoire and they would not find water in them, however thirsty they were. These are the lochs: Lough Derg, Lough Luimnig, Lough Corrib, Lough Ree, Lough Mask, Strangford Lough, Belfast Lough, Lough Neagh, Lough Foyle, Lough Gara, Loughrea, Marlóch. They would proceed to the twelve chief rivers of Ireland—the Bush, the Boyne, the Bann, the Blackwater, the Lee, the Shannon, the Moy, the Sligo, the Erne, the Finn, the Liffey, the Suir—and they would all be hidden from the Fomoire so they would not find a drop in them. But drink will be provided for the men of Ireland even if they remain in battle for seven years.