Snorri Sturluson's Prose Edda gives the Well of Urd a function as well as a location. Every day, he writes, the gods ride across the bridge Bifrost to hold their assembly there, which makes the well the closest thing Norse cosmology has to a seat of government rather than merely a scenic feature of the world tree. Beside it live the three Norns, Urd, Verdandi and Skuld, whose names are usually read as forms of what has become, what is becoming and what shall become, and whose task is to draw water and the white clay called aurr from the well and pour it over Yggdrasil's roots and trunk so that they do not rot and wither before their time.
The Voluspa, the Eddic poem that gives the fullest account of the cosmos from creation to Ragnarok, opens its account of the gods' early days with their assembly at this same well, setting their thing there from the very start of mythic time rather than treating it as a later arrangement. Two swans are said to live on the well's waters, and the poem calls them the ancestors of all swans afterward, one of the few notes in the sources that ties an ordinary living creature back to a specific mythic origin point rather than to a god's direct making.