Midgard (also spelled Midgarth), in Norse mythology, the Earth; the world of humans. Another name for Midgard was Manaheim. Midgard, literally "middle enclosure," the defensive fortress which the gods build about the middle portion of the earth allotted to men in order to protect mankind from the giants. was situated between the heavenly realm of Asgard and the foreboding wastes of Hel. It was also envisioned as being midway between Asgard and Jotunheim, the land of the giants. Asgard was described as a citadel in the clouds that rose up frpm the center of Midgard. To go from Midgard to Asgard one had to cross Bifrost, the Rainbow Bridge, which connected the land of humans and the land of the gods. Midgard was surrounded by an ocean, in whose deeps dwelled Jormungand, the evil serpent who was so large that he encircled the world, biting his tail with his mouth. One of the three roots of Yggdrasil, the World Tree, ended in Midgard.
Midgard, like Asgard and Jotunheim, was created by the first gods, the brothers Odin, Vili, and Ve, out of the body of the first frost giant, Ymir, whom they had killed. They formed Midgard specifically out of the giant's brow. Odin, Vili, and Ve also created the first man and woman, Ask and Embla, and gave them Midgard as their home; this is how Midgard became populated with humans.. . Midgard ("middle world") is on the same level as Nidavellir (land of the dwarfs), Svartalfheim (land of the dark elves/dwarfs) and Jotunheim (the land of the giants).
Midgard was surrounded by the Ocean. It was so wide that it was thought to be impossible for humans to cross. In the Ocean lurked the terrible World-Serpent, Jormungand. He was so big that his body circled Midgard and took his own tail in his mouth.