There are nine worlds from Norse mythology added to Minecraft by the "Isogild 9 realms" mod.
The mod makes an effort to replicate the Norse realms on which it is based. Players get a brand-new environment to explore in each dimension.
among the 9 realms are:
Asgard
Jotunheimr
Vanaheimr
Alfheimr
Niflheimr
Muspelheimr
Svartalfaheimr
Helheimr
the Overworld, too.
The Isogild 9 realms Team
