In
Gylfaginning by
Snorri Sturluson,
Gylfi, the king of ancient
Scandinavia, receives an education in Norse mythology from
Odin in the guise of three men. Gylfi learns from Odin (as
Jafnhárr) that Niflheimr was the first world to be created after Muspelheim: Odin (as
Þriði) further tells Gylfi that it was when the ice from Niflheimr met the flames from Muspelheimr that creation began and
Ymir was formed: In relation to the
world tree Yggdrasill,
Jafnhárr (Odin) tells Gylfi that frost jötnar is located under the second root, where Ginnungagap (
Yawning Void) once was: Gylfi is furthermore informed that when
Loki had engendered
Hel, she was cast into Niflheimr by Odin: Hel thus became the mistress of the world of those dead in disease and old age. This is the only instance in which Niflheim and Hel are equated (the Poetic Edda mentions Hel but doesn't say anything about Niflheim). However, there is some confusion in the different versions of the manuscript, with some of them saying Niflheim where others say Niflhel (the lowest level of Hel). Thus in the passage about the last destination of the
jötunn who was killed by
Thor after he had built
Asgard: ==
Hrafnagaldr Óðins==