Review
https://upload.wikimedia.org/wikipedia/en/9/93/WG5MordenkainenFantasticAdventureCover.jpg
I have always mused at the end of this that after finding the possibilites in the Tome of the Black Hand, that the Lost City of the Elder is :-
https://en.wikipedia.org/wiki/Cynosure_(comics)
This multiversal possibility leading to the ability to travel to any game universe. Gotham City, Ringworld, Glorantha, etc.