Bifrost is the rainbow bridge that connects Asgard, the realm of the gods and Midgard, the realm of man. The gods use it to travel between the two lands. Thor is the only god who will not use the bridge, fearing that his heavy tread and lightning bolts will destroy the bridge. Since this is the only way for the giants to enter Asgard it is closely guarded by Heimdall, the watchman of the gods. At the time the giants come to Asgard, Heimdall will blow his horn signalling to all the world the doom of the gods has begin.

Bifrost was made of three colors with magic and great skill by the Aesir and is incredibly strong. It is also called Asbru, referring to its makers. At the end of the cosmos, this rainbow-bridge will collapse.

Also known as: As-bridge, Asbru