Abzu

Abzû or Apsû (, + ) is the name for fresh water from underground aquifers which was given a religious fertilising quality in ancient near eastern cosmology, including Sumerian and Akkadian mythology. It was believed that all lakes, springs, rivers, fountains, rain, and even the Flood, as described in Atrahasis, originated from the Abzû. In Mesopotamian cosmogony, it is referred to as the freshwater primordial ocean below and above the earth; indeed the Earth itself was regarded as a goddess Ninhursag that was conceived from the mating of male Abzu with female saltwater stream Tiamat. In this worldview, our divine Mother Earth—equipped in her upper half with a bubble of air from the breath of the most ingenious god "Lord Wind" Enli—thus is surrounded by cosmic freshwater and encircled at her edge by that saltwater river. Through the underground of her body, which also contains the Irkalla as a special compartment for the dead's live on there as shadows, runs a tunnel drilled by the sun god Shamash himself, allowing his burning fire during night to rush dry-footed from west to east, where he begins to rise again between the peaks of the Zagros Mountains.

Abzû in Sumerian is also called (cuneiform: , ); in Akkadian (), and in Akkadian: . In Greek Abzû is recorded as .