In Norse mythology’s Ragnarok, Surtr and the fire giants come from Muspelheim.
Muspelheim is a fiery realm associated with heat, flames, and the fire giants. Surtr, its prominent ruler or guardian in later descriptions, leads these forces during the final conflict between the gods and their enemies.
The fire giants cross Bifröst as the forces of destruction advance. Their passage helps bring about the bridge’s breaking, and Surtr later sets the world ablaze. Muspelheim is therefore more than a battlefield location: it is the source of the fire that consumes the old world.
Muspelheim is commonly contrasted with Niflheim, the cold, mist-filled realm. Some surviving sources give limited geographic detail, and modern fantasy works often expand the realm far beyond what medieval Norse texts explicitly describe.