Boann in Celtic Mythology
There are a couple of variations on the myth of the goddess Boann, but one element tends to remain the same - she was the wife of Nechtan, a god of the water. Likewise, Boann was herself a water-goddess, and one of her myths concerns the water. According to legend, there was a sacred well (Sidhe Nechtan) that contained the source of knowledge. All were forbidden to approach this well, with the exception of the god Nechtan (as was noted, Boann’s husband) and his servants. Boann ignored the warnings, and strode up to the sacred well, thus violating the sanctity of the area. For this act, she was punished, and the waters of the defiled well swelled and were transformed into a raging river, a river that pursued her. In some versions, she was drowned; while in others, she managed to outrun the currents. In either case, this water became the river that was known henceforth as the Boyne, and Boann thereafter became the presiding deity.
Another aspect of the myth of Boann is that she bore Oenghus. She and the leader of the Tuatha De Danaan, the Dagdha, engaged in an illicit affair that resulted in the birth of this god of love. However, since both Boann and the Dagdha wished to keep their rendezvous a secret, they used their divine powers to cause the nine month gestation period to last but a single day - or so it seemed, for the sun was frozen in the sky for those nine months, never setting and never rising. On this magical day, Oenghus emerged into the world.