I find Yggdrasil to be somewhat confounding, but maybe that’s because the Edda isn’t exactly the clearest of texts. But I’m going to try to patch it all together in a way that I understand and, hopefully, you will as well.
Simply put, Yggdrasil is the world tree in Norse mythology. The branches spread out across the sky and heavens. It has three great roots that extend great distances. One of these roots extends over Niflheim—a frozen realm of ice and mist. The dragon Nidhogg gnaws at the bottom of this root. Underneath it is also the spring Hvergelmir.
The second root extends to the realm of the frost giants. Underneath this root is Mimir’s well. Mimir was apparently a master of knowledge, gaining his wisdom from drinking water from the well. Odin had to give up one of his eyes for a single sip.
The third root extends up to the heavens and to the realm of the Aesir. Underneath this root is Weird’s well. This is where the Aesir hold court, and they ride there every day by crossing the rainbow bridge Bifrost. Apparently the red in the rainbow signifies burning fire, and keeps unsavory giants from going up into heaven. The norns that live by Weird’s well use the water to keep Yggrasil from rotting. For this reason, Weird’s well is the holiest of all the wells, and anything that comes in contact with it turns white. Two swans feed in the well, and are said to be where all swans in the world have originated.
In the middle of all this is Midgard. The index in the Edda translates it as “middle enclosure” and describes it as “the rampart surrounding the world of men and protecting it from giants” (Sturluson p. 247). I wrote about that rampart in an earlier post. This is where my head starts to hurt. But let’s dive in.
This realm is described as being circular, with the sea on the outer edge. Along the shore of the sea live the races of giants. Then there is a fortification that separates the world from the hostile giants, “and for this fortification they used the giant Ymir’s eyelashes, and they called the fortification Midgard.” (Sturluson p. 12, 13). It’s stated later that the first man and woman, Ask and Embla, were given a place to live under Midgard. I’m not sure why it’s “under” and not “within”. The best I can figure is maybe the fortification is more like a bubble, rather than a wall (which is what I think of at the mention of “fortification”.) Anyway, apparently Ymir’s brains were also used to make the clouds in the sky. Think about that next time you’re finding cute bunny shapes in the clouds above.
This all makes my head hurt because certain details overlap without any explanation being given. It’s said that Ymir’s eyelashes were used to construct Midgard, but then there’s another story of a giant building the fortification without any mention of eyelashes. Is this the same fortification, or is it completely different? Also, the land of the giants is on the shores of the world outside of Midgard. But then, the realm of the frost giants is down by one of Yggdrasil’s roots. Does this root extend up to Midgard just as one of the roots extends up to Asgard? I don’t know. I find it all very convoluted. Perhaps my issue is that I’m trying to get a clear picture of it, which is probably not the point of these myths. But I’m not the only one trying to understand, as this lovely picture attests.
If you have a better understanding of Norse cosmology, please chime in. I’d love to read a clear explanation of it all.
Source: Sturluson, Snorri, Edda, Everyman, 1995. Translated and edited by Anthony Faulkes.