Ymir's skull, Norðri, Suðri, Austri and Vestri

[The Perilous Dreamer]

Ymir's skull, Norðri, Suðri, Austri and Vestri each support one of the four cardinal points. Together, they uphold the heavenly dome, created from the skull of the jötunn Ymir. (Norse mythology)

[The Perilous Dreamer]

Ymir

The gods Odin, Vili and Vé fashioned the Earth (elsewhere personified as a goddess; Jörð) from his flesh, from his blood the ocean, from his bones the mountains, from his hair the trees, from his brains the clouds, from his skull the heavens, and from his eyebrows the middle realm in which mankind lives, Midgard. In addition, one stanza relates that the dwarfs were given life by the gods from Ymir's flesh and blood (or the Earth and sea).