According to Celtic myth, Anu (or Ana) is a fertility priestess and a Celtic culture heroine. She is honored especially in Munster where two mountains in Killarney are known as the Da Chich (N)Anann, the “Paps of Anu.” This is known as one of the homes of the Tuatha de Danann.
Anu is closely associated with Danu, the mother and deity of the Tuatha de Danann, as well as the Welsh goddess Don. Though little is known of this goddess now, some scholars feel here character was merged into that of Brighid. Aine, the moon goddess and patroness of cattle and crops, is also considered one of her aliases. She has been included in the triad of the Morrighan with Badhbh and Macha. In addition, Anu has been identified with the man-eating Black Annis, a blue-faced hag akin to the Cailleach Bheare. Black Annis lives in a cave in the Dane hills in Leicestershire.
Some sources say that Anu is the true form of the goddess of the Tuatha de Danann however, and Danu was a corruption of the original name. Danu is the niece of Dagda and daughter of his brother Delbaeth. She is mother of Brian, Iuchar, and Iucharba.
According to Babylonian myth, Anu (or An) is a sky god, the son of Anshar and Kishar. His name means “Expanse of Heaven.” He is chief in a great triad of gods which includes Enlil and Ea. Anu is usually referred to as the Supreme King of Heaven, Father of the Gods, and Ruler of Destiny. He was worshipped mainly at Uruk and Der where his chief festival was the Akitu in Babylon.