The sea has claimed all Our pride has sunk below Where once flags flapped bright No sign or ruin gives note Tall spires were felled low White walls crashed down like foam The waves have rolled through Our hearths are dead and cold Fair gems have waned dark Their light shines no longer All songs have ceased now The joyful live no more A cloud has risen here It's shadow leads the van
The Tuatha Dé Danann abandoned Murias, Falias, Gorias and Findias in the northern islands of the world and colonized Ireland. In my interpretation, the cities sank beneath the ocean.