George R. R Martin's Failed 1992 Multiverse Doorways television pilot

 https://www.looper.com/1304414/george-r-r-martins-failed-1992-multiverse-show-doorways-deserves-reboot/ 

The potential is still there, because of CGI and AI. A revamped TV pilot could use the original actors, plus any new actors and characters. 

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

George RRM could do a total update, expanding upon his original concept.

https://www.ranker.com/list/doorways-lost-george-rr-martin-tv-pilot/shamus-kelley

https://www.businessinsider.com/george-rr-martin-doorways-tv-show-before-game-of-thrones-2015-11 

https://georgerrmartin.com/notablog/2010/07/24/doorways-coming-in-november 

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

Not just in Sci-Fi stories, symbolic everyday portals can be perceived.

https://www.tom-cox.com/the-20-best-interdimensional-portals-i-have-photographed-on-walks-in-the-british-countryside/