i think you need a e-reader to skan Pokemon cards(trainer card=trainer in back room
Pokemon card=Pokemon in back room, this might work in sapphire & rube aswell).
The trees are blocking an inaccessible area in Sootopolis City on Pokemon Emerald. This area was accessed with the E-Reader however the cards needed to unlock it were never released.
under sootopolis
in sootopolis city
Go to Sootopolis.
sootopolis city
underwater near sootopolis city
well i forgot
Sootopolis city.
The Pokemon league!
you have to distory the door
simpliy the dark spot leading to sootopolis you have to use dive
Underwater, in the grass outside Sootopolis City.