User blog comment:CNBA3/Dragon's Location Theory!/@comment-7070784-20140709050341

If a different world exist then maybe aside from the dragons going from their world and into earth land its also possible that the young dragon slayers got lost and ended up in the dragon's world, and in that world time passes differently thats why gajeel and natsu wasnt able to get out of freed's runes.

Its also possible that the dragons can still sense their children just like when igneel and grandeeney talks about natsu in the tower of heaven arc, i dont think that their conversation is a flash back since first igneel is in a volcanic area and no longer with natsu and lastly if it were a flash back natsu would still be a child and who would he be fighting for grandeeney to mention that natsu takes things in excess, or talk to their counterpart like how grandeeney gave porlyusica the instructions of the 2 spells.

I remember that grandeeney mentions the dragon king feast to igneel maybe that event was in the dragon's world.

Its also possible that the dragon civil war resulted in the separation of the dragons and the humans leading the rest of the dragons to go to or be sent to a different world which is not the dragon's world. Since the dragons already know zeref and theres a possibility of zeref being related to the creation of Acnologia, maybe they will come back to earth land to help defeat zeref which is a possible thing if ever the dragons do return.

And the death of layla is also related to the opening of the dragon's world and the return of the young dragon slayers in earth land making them think that the dragons vanished.

Since mashima tend to get ideas from Rave Master the existence of a diff world is possible, specially since there is already a celestial world and edolas.