Niflheim

A realm that has existed since time immemorial, Niflheim is the thematic opposite to fiery Muspelheim. Called Niflheimr in Old Norse, this realm is full of ice, mist, and not much else. Located under the third root of Yggdrasil, one thing that does lie here is the well Hvergelmir.

A bubbling, boiling spring, this feeds one root of the world tree and is the source of all cold rivers as well as the 11 mythological rivers in Norse sagas. It is said that this well is the origin of all living things and to where all will one day return. One creature that is said to inhabit this dark, cold realm is the dragon Nidhogg, who gnaws at the root of Yggdrasil.

Often, this realm is confused or conflated with Helheim. This may be due to the place known as "Niflhel" referred to in some texts. No one is sure of the borders, though the two realms are thought to be very close to one another, with the rivers of Niflheim falling into Helheim below. However, some believe that there is actually overlap between the realms, or that Helheim is a walled kingdom within Niflheim itself.