Nirn - (believed to mean ‘Arena’ in Old Ehlnofex) is the only habitable planet. It floats in the void of Oblivion and is, for all intents and purposes, the majority of the realm known as Mundus. You’ll hear people merge the distinguishes between Nirn and Mundus, but, despite the resemblance of theirs, they are different. Our planet was created during the Dawn Era by the Aedra and Anu-aligned spirits, based on Lorkhan’s inspiration and the God of Sorcery, Magnus’ designs. Since then it has fallen and prospered, grown and shrunk during the dark and holy ages of men and mer.