Benben or Ben-ben, in Egyptian mythology, specifically in the Heliopolitan tradition, was the mound that arose from the primordial waters, Nu, and on which the creator god Atum settled. In the Pyramid Texts, e.g. Utterances 587 and 600, Atum himself is at times referred to as "mound". It was said to have turned into a small pyramid, located in Annu, which was the place Atum was said to dwell within. Other cities developed their own myths of the primeval mound. At Memphis the god Tatenen, an earth god and the origin of all things in the shape of food and viands, divine offers, all good things was the personification of the primeval mound.
The Benben stone, named after the mound, was a sacred stone in the solar temple of Heliopolis. It was the location on which the first rays of the sun fell. It is thought to have been the prototype for later obelisks, and the capstones of the great pyramids were based on its design. Their tips (pyramidia) were probably gilded. The phoenix, the bennu bird, was venerated at Heliopolis, where it was said to be living on the Benben or on the holy willow. According to B Kemp the connection between the benben, the phoenix, and the sun may well have been based on alliteration: the rising, weben, of the sun sending its rays towards the benben, on which the benu bird lives. Utterance 600 of the Pyramid Texts speaks of Atum as you rose up, as the benben, in the Mansion of the Benu in Heliopolis (Hart, p.16).