Valhalla

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Asgard is one of the nine worlds in Norse Mythology unified by the world tree Yggdrasil, and is the citadel of the Norse gods. Valhalla is located within Asgard, ruled by Odin and his wife Freya. It was located in the heavens and accessible only over the Rainbow Bridge,Bifrost.  

 Valhalla was the most splendid palace in Asgard.  It was overseen by the Valkyries, female warrior deities sent by Odin to every battle to select and carry the most heroic warriors slain in battle off to Valhalla.  They would become the "einhar" (lone fighters) who were to fight at Odin's side at Ragnarok, the final battle in which the giants and demons would overcome the gods.