"Ginnungagap is the abysmal gap of origin which forms the border between (ie, at once separates and joins) the northern ice and the southern fire. It is out of this gap through the action of the giants and gods that the world is born - middle earth (Miðgarð).
As with the Greeks, the mystery lies in the joint of what belongs below (ice, north, night, giants) with what belongs above (fire, south, day, gods). It is the nature of human being, the creatures of Miðgarð, to be subject to this mystery and to the care and anxiety which follow from its difficult complexity."
Gigantomachia A fascinating site researching the theme of historic wars between gods and giants.