Spirit Realm

These are the dimensions or alternate planes of existence created by and mostly inhabited by spirits. Most of them were created as new dimensions by deities or creatures with vast power rivaling that of a god.
Since they aren't connected by land, it's normally impossible to enter or leave one of these realms by physical means like walking. The method of entry varies depending on each individual spirit realm, but peculiar spells, rituals, portals (teleportation spells), or the assistance of a specific race are necessary.

Geography

Types of spirit realms

Aether 

The spirit realm that exists parallel to the physical world it is based on.

Godrealms

Spirit realms created by deities and other divinities to inhabit. Sometimes they also allow the departed souls of their followers to dwell there as well.

• Olympus
• Svarga 
• Aaru
• Asgard
• Vanaheimr
• Takamagahara
• Tian
• Tír na nÓg
• Tlalocan
• Garden of the Hesperides
• Land of Manu
• Panchaia
• Vaikuntha

Afterlives

Spirit realms created for the departed souls of a deities followers.

• Mag Mell
• Asphodel Meadows
• Hel
• Hamistagan
• Elysium

Underworlds

Spirit realms created for the departed souls rejected by various deities, typically for committing many evil acts without repentance.

• Hades
• Naraka
• Tartarus
• Yomi
• Niflhel
• Xibalba
• Diyu
• Irkalla

Otherworlds

Intermediary spirit realms created by powerful/intelligent non-divine spirits.

• Summerland
• Alfheim
• Annwn
• Svartálfaheimr
• Jötunheimr
• Muspelheim
• Midgard

Type

Dimensional plane