Dubad (Dowth)

Dubad, whence the name? Not hard to say. A king held sway over Erin, Bressal bó-dibad by name. In his time a murrain came upon the kine of Erin, until there was left in it but seven cows and a bull. All the men of Erin were gathered from every quarter to Bressal, to build them a tower after the likeness of the Tower of Nimrod, that they might go by it to Heaven.

His sister came to him, and told him that she would stay the sun's course in the vault of heaven, so that they might have an endless day to accomplish their task. The maiden went apart to work her magic. Bressal followed her and had union with her: so that place is called Ferta Cuile from the incest that was committed there. Night came upon them then, for the maiden's magic was spolit.

'Let us go hence,' say the men of Erin, 'for we only pledged ourselves to spend one day a-making this hill, and since darkness has fallen upon our work, and night has come on and the day is gone, let each depart to his place.' 'Dubad (darkness) shall be the name of this place for ever', said the maiden. So hence are Dubad and Cnoc Dubada named.

Source:
Metrical Dindshenchas. ed and trans. Edward Gwynn. 1925. Dublin: Dublin Institute for Advanced Studies: 1991.