I believe these tuatha de danann are the small Danes, who, according to tradition, built the raths and souterrains.
I know that some high authorities regard the tuatha de danann and the fairies as alike mythological beings.
What is here averred of the tuatha de danann may be true of other primitive races who may have survived long in Ireland.
But Oengus is not the only one of the tuatha de danann who has such a fairy palace.
Galway, reputed to be the headquarters of all the tuatha de danann and shee-folk of Connacht.