Interdimensional Doorways

 https://www.reddit.com/r/TopCharacterTropes/comments/1qu9g16/interdimensional_doors/ 

https://vocal.media/futurism/beyond-the-veil-do-portals-to-other-realities-exist

https://tvtropes.org/pmwiki/pmwiki.php/Main/PortalDoor 

https://marvelcinematicuniverse.fandom.com/wiki/Inter-Dimensional_Portal 

https://ultimatepopculture.fandom.com/wiki/Interdimensional_being

https://dexterslab.fandom.com/wiki/Inter-Dimensional_Doorway 

https://robertscheer.net/aramu-muru-portal 

https://georgerrmartin.com/notablog/2023/12/13/a-blast-from-my-past DOORWAYS

https://www.dictionary.com/browse/interdimensional and Inter-dimensional 

https://worldbuilding.stackexchange.com/questions/166651/what-s-the-difference-between-inter-dimensional-inter-universal-and-extra-dime 

https://therabbitportal.blogspot.com/search?q=Interdimensional+Doorways