Bifrost/Asabridge/Asbru

The Bifrost is a magical location from Norse mythology. It’s translated as “rainbow bridge” or “the trembling way.”  It’s thought to connect the earth, Midgard, to the world of the gods, Asgard, by spanning across the sky. It’s constructed of three fragile-looking strands of air, fire, and water, though despite its weak-looking structure it’s impossibly durable. It’s believed that the god Heimdall guarded the bridge to prevent the Jötnar from crossing. He was given this duty due to his remarkable senses, and since he has a magic horn to alert the entire nine realms of danger. Most all the gods use to bridge to travel on horseback, aside from Thor who has to wade through rivers since his presence would destroy the Bifrost. The prophecy of Ragnarok states the Bifrost is destined to be destroyed by the forces of Muspelheim.

Citations:

Bane, Theresa. Encyclopedia of Imaginary and Mythical Places. United States, McFarland, Incorporated, Publishers, 2014.