In Norse mythology, the dead cross the river Gjöll using the bridge Gjallarbrú on the journey toward Hel’s realm. The river’s name is also written Gjǫll or Gjoll in modern references.
The story appears in the account of Hermóðr’s journey after Baldr’s death. Hermóðr rides toward Hel and reaches Gjallarbrú, a bridge guarded by the maiden Móðguðr. She tells him that Baldr has already crossed and that the bridge sounded beneath him because he was alive rather than dead.
Gjallarbrú is distinct from Bifröst, the rainbow bridge connecting Midgard and Asgard. The two bridges belong to different mythic journeys and should not be treated as alternate names for the same structure.
The river Gjöll is also associated with the rock where Fenrir is bound in some accounts. Norse place names can recur across different episodes, so context matters when identifying a river, bridge, or boundary in the underworld stories.