Jötunheim

Jötunheimr was one of the nine worlds of YGGDRASIL.

Background
The World Tree YGGDRASIL had countless leaves, but then a gigantic monster appeared which devoured these leaves, causing them to fall one after the other, until only nine were left. These nine leaves were the previous incarnations of the Nine Worlds, particularly Jötunheimr. However, the leaf-eating monster continued its advance to the point where it devour the leaf representing Jötunheimr. This was the backstory upon which the players adventured into the world of Jötunheimr in order to protect it.

Jötunheimr was one of the realms where many players of the humanoid and demi-human races mainly resided in.

The world was described to be ridiculously huge, and there were many places within it which were difficult to explore. For instance, there were many areas which required the use of special equipment along with a proper strategy and the determination in order to delve into its hard-to-find dungeons that drop valuable Data Crystals.

Jötunheimr is revealed to be a world for ancient frost dragons. During the course of hunting these said monsters for materials like meat, they can be served as ingredients for making food like marbled steak. It seems apparent that the Great Tomb of Nazarick has at some point in the past, manage to acquire such raw material from them.

Within Jötunheimr, things became more dangerous the further one went from the center of its world. In addition to the wandering monsters, the very terrain itself became a hazard for players to explore.

Features
A developer-sanctioned tournament was held in this world where one could become a World Champion and acquired a special powerful equipment awarded as the winner's price for exclusive use with that class. Only one player with the World Champion job class was allow to exist in Jötunheimr. There is also just one guild base in this world that contains 3000 levels of NPC Data Storage which is highest amount by far available.

Trivia

 * This world has its own particular traits, but they often shared one similarity which is the fact that it is two to three times the size of Tokyo.
 * Some guild members of Ainz Ooal Gown had once thought of trying to conquer one of the worlds in YGGDRASIL.
 * During an argument with Touch Me, Ulbert Alain Odle wanted Ainz Ooal Gown to farm for frost dragons to fulfill one of their guild member's class-up requirements. "The Ice of the Beginning" item is most presumably in this world based on the fact it is dropped by these dragons.
 * In a tournament battle consisting of only the World Champions as participants, the first-place champion of the overall tournament was the Jötunheimr's World Champion.