are described as lying within Asgard including Valhalla, and in front of its doors, the golden grove Glasir. It also records a name for Thor as 'Defender of Ásgard' (). Ynglinga Saga In the Ynglinga saga, found in Heimskringla, Snorri describes Asgard as a city in Asia, based on a perceived, but erroneous, connection between the words for Asia and Æsir. Odin then leaves to settle in the northern part of the world and leaves his brothers Vili and Vé to rule over the city. When the euhemerised Odin dies, the account states that the Swedes believed he had returned to Asgard and would live there forever. Interpretation and discussion Cosmology in Old Nordic religion is presented in a vague and often contradictory manner when viewed from a naturalistic standpoint. Snorri places Asgard in the centre of the world, surrounded by Midgard and then the lands inhabited by , all of which are finally encircled by the sea. He also locates the homes of the gods in the heavens. This had led to the proposition of a system of concentric circles, centred on Asgard or Yggdrasil, and sometimes with a vertical axis, leading upwards towards the heavens. There is debate between scholars over whether the gods were conceived of as living in the heavens, with some aligning their views with Snorri, and others proposing that he at times presents the system in a Christian framework and that this organisation is not seen in either Eddic or skaldic poetry. The concept of attempting to create a spatial cosmological model has itself been criticised by scholars who argue that the oral traditions did not form a naturalistic, structured system that aimed to be internally geographically consistent. An alternative proposal is that the world should be conceived of as a number of realms connected by passages that cannot be typically traversed. This would explain how Asgard can be located both to the east and west of the realm of men, over the sea and over Bifröst. It has been noted that the tendency to link Asgard to Troy is part of a wider European cultural practice of claiming Trojan origins for one's culture, first seen in the Aeneid and also featuring in Geoffrey of Monmouth's Historia regum Britanniae for the founding of Britain. Depictions in popular culture Thor first appeared in the Marvel Universe within comic series Journey into Mystery in the issues