Ginnungagap is the bottomless abyss that was all there was prior to the beginning of the cosmos, and into which the cosmos will collapse once again during Ragnarok, the “Twilight of the Gods,” only to be reborn as the cycle completes itself. As the Eddic poem Völuspá, “The Insight of the Seeress,” describes the time before the cosmos existed:
That was the age when nothing was;
There was no sand, nor sea, nor cool waves,
No earth nor sky nor grass there,
–from Norse Mythology for Smart People by Daniel McCoy
Once there was nothing but fire and ice. As the flames and frost drifted towards one another, meeting finally at Ginnungagap, the ice began to melt. From the drops the first creature, the giant Ymir, arose. From Ymir’s sweat more giants were born, and from the frost arose a cow named Audhumbla.
Audhumbla licked the ice and uncovered Buri, the first of the Aesir. Buri had a son, Bor, who married the giant Bestla, and they had three half-god, half-giant sons, Odin, Vili, and Ve. The three brothers slew Ymir and created the cosmos from his body.
The gods eventually created the first two humans, Ask and Embla, and built a wall around the place they created for them, Midgard, in order to protect them from the giants.
The giants in Norse mythology are always to be feared. The gods took many precautions to keep the giants from crossing into Asgard and Midgard. But they failed.
Eventually, the giants defeated the gods at Ragnarok and dragged the cosmos back to Ginnungagap. Ragnarok is not only the coming end of the world; it was the end of the world in the past. Out of Ginnungagap, the cosmos arose and will rise again. And the cycle of Norse mythology continues.
 The Poetic Edda. Völuspá, stanza 3. Translation by Daniel McCoy. The original Old Norse text is as follows:
Ár var alda,
þar er ekki var,
var-a sandr né sær
né svalar unnir;
jörð fannsk æva
gap var ginnunga
en gras hvergi.
Image credit: Daniel McCoy, Ginnungagap.