I dunno, lol, I just went and it was there
i'll google it
this is what i got from serebi.net
How do I get there (If it's real)?
Every Day, a random number is generated by your game and for each of your Pokémon. You Pokémon's random number changes when you put it in the box...if your number matches...Mirage Island becomes available...but its only there for a day...maybe less if you deposit the Pokémon. You can tell if its there through the man in the bottom right house on Pacifidlog Town
What Pokémon Inhabit this elusive Island?
Only One Kind of Pokémon inhabit's this island. They are Wynaut, the Pre-evolved form of Wobbuffet:
They are the only Pokémon here and range in levels from Level 5 all the way up to Level 50
I see a Berry Patch, What sort of Berry Comes from there?
Only the rarest Berry accessible in the game. Berry #36 a Liechi Berry. This Berry is easily used to make Gold Pokéblocks...the best and strongest Pokéblocks
Pretty cool eh? lol.
it goes by your pokemon id numbers
Yes thats VERY cool
thanks for all that really cool information potato_chips