Muspelheim, (also spelled Muspellheim), in Norse mythology, one of the nine realms of the universe, a glowing, hot region of fire that existed since the beginning of time. According to the 'Prose (or Younger) Edda', Muspelheim was a fiery realm of destruction located in the southern part of the primordial void known as Ginnungagap. It had been there long before the gods created heaven and Earth. No one could survive in Muspelheim who did not belong there; it was home only to a race of fire giants. The foremost of these, a mysterious, menacing figure named Surt, stood eternal guard at the borders of Muspelheim, brandishing his flaming sword.
In contrast to Muspelheim was Niflheim, the bleak realm of poisonous ice and fog that lay in the northern region of Ginnungagap. In the central place where the two opposing realms interacted, Niflheim's ice was melted by the heat and energy of Muspelheim; the first being, the frost giant Ymir, was formed from these drops of moisture.
The principal god Odin and his brothers, Vili and Ve, killed Ymir and made all the lands of the Earth, the ocean, and the sky from his body. They used sparks from Muspelheim which flew about in the air to create the heavenly bodies and the stars, placing them in the heavens and setting them on their courses.
According to Norse myths, at Ragnarok, the final battle between the forces of good and evil, Surt would go forth from Muspelheim, leading all the fire giants across Bifrost, the Rainbow Bridge that connects the world of humans with heaven, breaking the bridge in the process. The fire giants then would lay waste to the home of the gods and destroy the whole world