Percy Jackson and the Olympians: Legends

Niflheim is one of the Nine Worlds, more specifically the primordial world of ice and frost. It was one of the first two worlds in existence, alongside Muspelheim. The only known plant life able to grow in Niflheim appears to be the Raven Tree, a giant tree whose trunk is sheathed in jagged, massive ice crystals, suggesting that native life is possible though no fauna can be found here. The closest thing to animal life that exists are the souls of Odin's Ravens, who roost in the tree. The Mist Fields also have several structures including Nordic stone statues and a metallic female statue covered in snow, far from the canyons where the pieces of the enormous skeletal corpse of Auðumbla, the Primordial Cow, laid in their final resting places. It is also known as the World of Dark Mist, and is the land from which eleven poisonous rivers run.

Niflheim is known as the land of ice and mist. It is barren and cold, with the highest temperature in the warm regions being 40 degrees below freezing. It is primarily made of ice, although there are black mountains which can host fortresses, like Skadi's. Niflheim has a gigantic spring at its center, known as Hvergelmir. This pool is the mother of all rivers and springs, and is the source of eleven poisonous rivers that run through Niflheim.