What metaphors are used in Mythology by Edith Hamilton?

Valhalla is a metaphor for transcendence. In the Norse myths, Valhalla was the realm where heroes, or those who died gloriously in battle, went to when they died. They were brought there by battle-maidens called Valkyries. They dwelt there happily until the end of the world (Ragnarok), when they were destined to fight on the side of the gods against the frost giants.