In Norse mythology, the Norns are the demi-goddesses of destiny. They control the destinies of both gods and men, as well as the unchanging laws of the cosmos. They are represented as three sisters: Urd ("fate"), Verdandi ("necessity") and Skuld ("being"). They live at the base of the World Tree Yggdrasil in the realm of Asgard.
Nothing lasts forever, and even the mighty Yggdrasil is subject to decay. The Norns try to stop this process, or at least slow it down, by pouring mud and water from the Well of Fate over its branches. This magical liquid stops the rotting process for the time being.
In other myths, the Norns were thought to give assistance at birth, and that each person has his own personal Norn. (Meaning there are more than three.)
According to Norse mythology, the wall that enclosed Asgard was destroyed during a war between the Vanir and the Aesir, leaving the gods vulnerable to an attack by the giants.
One day, an itinerant stonemason named Blast came to Asgard and offered to rebuild the wall if the goddess Freya would consent to be his wife. He asked for the sun and the moon as well. The gods wanted the wall rebuilt but the terms stated by the mason were outrageous. However, the god Loki proposed a way of outwitting the mason and getting at least part of the wall rebuilt for nothing. The gods agreed to the payment asked by the mason, but only if the work was completed within six months. The mason insisted that he be allowed to use his stallion, Svadilfari, in rebuilding the wall.
The work proceeded much more rapidly than the gods had anticipated and they began to worry that the mason might have to be paid after all. The god Odin threatened to kill Loki if the wall was completed within the allotted time. Loki saw that the mason's horse was doing the heavy hauling and he devised a plan to deprive the mason of the help of his horse. Taking the form of a young mare, Loki lured the stallion into a thicket and made sure that he remained there until the next day. When Svadilfari returned to his master it was too late to complete the work. The mason became so angry that he revealed his true form, that of a rock giant. The god Thor dispatched the giant with a mighty blow of his hammer, Mjollnir.
Months later, Loki returned to Asgard. He brought with him a gray colt with eight legs, the foal of Loki the mare and Svadilfari the stallion. He gave it to Odin, saying that its name was Sleipnir. The colt could travel over land and sea and through the air.
The nine worlds of Norse mythology.
The first level: Asgard, world of the Aesir; Vanaheim, land of the
Vanir; and Alfheim, land of the light elves.
The second level: Midgard, Land of humans (middle world/garden);
Nidavellir, Land of the dwarfs; Jotunheim, Land of the giants (Jotuns);
and Svartalfheim, Land of the dark elves.
The third level: Hel, Realm of the dead; and Niflheim, World of
the dead.
If Hel and Niflheim comprised one world, as is suggested in some sources, the ninth may have been Muspelheim (Muspell), the land of the fire giants. This region had no place in the tricentric structure of the universe, and Snorri Sturluson wrote that is was the first world to exist and that is lies in the southern hemisphere. Also, the worlds of Svartalfheim and Nidavellir may have been the same. No valid distinction can be drawn between the dwarfs and dark elves; they appear to have been interchangeable.
An alternate reference of the Nine Worlds :
