Asgard is one of the Nine Worlds of Norse mythology and the home and fortress of the Aesir, one of the two tribes of gods, the other being the Vanir, who have their home in Vanaheim. Asgard is located in the sky, albeit invisible to the eyes of mortals, and is connected to Midgard, the world of humanity, by the rainbow bridge Bifrost.
Asgard plays a central, if not always well-articulated, role in the exploits of the Aesir. More specifically, as the primary heavenly realm in the Norse cosmological scheme, it was understood as the place where the gods dwelt, interacted with each other, and surveyed their human constituents.
Descriptions of the various dwelling-places of the Aesir, homes that were always conceptualized as being analogous to the castles and feasting halls of human royalty, were fairly common in mythic texts (and, one can assume, in the skaldic poems that they were based upon).
Asgard also featured numerous other mythical important geographical elements. The city of the gods was set upon the splendid plains of Idavoll, a bounteous field where the Aesir would meet to discuss important issues. It was also the location of Yggdrasil's third, world-anchoring root, under which was located the Well of Urd. This well, which was cared for by the Norns, was understood to fulfill two functions: It nourished the World-Tree and was somehow related to destiny or to prophetic wisdom.
While Asgard is to be destroyed at the great battle of Ragnarök, the second-generation deities that will survive the apocalypse are prophesied to rebuild it, ushering in an new era of prosperity. Other religions, too, speak of cosmic renewal and restoration after a long process of divine providence.