World of the Vanir; Njörðr, Freyr, and Freyja come from there.

Vanaheimr is the home of the Vanir gods, one of the nine worlds in Norse cosmology. The Vanir, including Njörðr, Freyr, and Freyja, form a class of deities distinct from the Aesir and are associated with fertility, wealth, and seiðr magic. The exact location of Vanaheimr within the cosmology is never clearly specified in the surviving sources.

The Aesir-Vanir war, the first war in mythology, broke out when Gullveig, probably a Vanir goddess associated with gold and seiðr, arrived in Asgard and was repeatedly killed and revived by the Aesir. The war ended with a peace treaty in which valuable hostages were exchanged, bringing Njörðr, Freyr, and Freyja to Asgard and sending Hönir and Mímir to Vanaheimr.

Vafþrúðnismál 39 is one of the few direct source references to Vanaheimr as a place: the giant answers Odin's question about Njörðr's origin by stating that he was created in Vanaheimr by wise powers and sent as a hostage to the Aesir. This passage is pivotal for understanding Njörðr's origin and the existence of Vanaheimr.

Since Freyr and Freyja are children of Njörðr and an unnamed sister, their origin is also considered to lie in Vanaheimr. Freyja's speciality, seiðr magic, is said in Ynglingasaga to have been taught to the Aesir by her, suggesting that Vanaheimr is associated with this type of magic.

Sources in the Eddas

Vafþrúðnismál 39
The only Poetic Edda source to directly name Vanaheimr as Njörðr's place of origin.
Völuspá 21-24
The Aesir-Vanir war and Gullveig's role are described, without Vanaheimr being explicitly named.
Skírnismál 1-3
Freyr's background as a Vanir god is presented in the introductory prose.
Lokasenna 33-34
Freyja's and Njörðr's Vanir background is referenced in connection with accusations of incest.

Interpretive traditions

A What we know

Vanaheimr is the home of the Vanir gods, confirmed in Vafþrúðnismál 39.

Njörðr, Freyr, and Freyja are originally from Vanaheimr and came to Asgard as hostages after the Aesir-Vanir war.

B What we think we know

Gullveig's exact identity and whether she was a Vanir goddess or another type of being is debated.

Whether the Aesir-Vanir war reflects a historical conflict between different cult practices or population groups is disputed among scholars.

C What we do not know

Vanaheimr's geographical placement relative to the other nine worlds is entirely unknown.

Whether Vanaheimr exists separately at Ragnarök or dissolves along with the other worlds is unclear.