you've got to find kyogre and groudon, stop team magma and aqua from doing what ever to them then go to the cave that the old man is blocking in sootopolis city and you can go in
beat the 8th gym
sootopilis city
Go to Sootopolis.
...... stewen in emerald isn't a elite champion. there is wallace.
sootopolis city
i go to mossdeep city
somebody gives it to us after beating the 8th gym
in the fortree city
Wallace he was the former 8th gym leader in ruby and sapphire
Dude, this isn't the way of a question.It has to be:" Where is Southopolis on Pokemon emerald"!!The answer is:If you mean Sootopolis City, than it's the 8th GYM.You have to dive and go to there.
In Sootopolis City.Trainers and Gym Leader uses Water-Type Pokemon.
Find the key at a under water cave