Bifrǫst ('swaying road to heaven' from Old Norse bifa = 'shake, sway'; it could also derive from Bilrǫst) is the name of the rainbow, the bridge between Ásgarðr and Miðgarðr. It ends in the sky at Himinbjǫrg where Heimdallr lives. He guards the bridge from the giants.
Another word for the bridge is Ásbrú because every day the Æsir ride over to their court at the Urðarbrunnr. At Ragnarǫk the hostile sons of Muspell will ride over Bifrǫst, and then it will collapse.
- ↑ Rudolf Simek: Dictionary of Northern Mythology (1993)