beat the other gyms and it will open. It is giovanni
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DO NOT LISTEN TO THAT ONE
You are supposed to get to the underwater cavern and beat team magma then go to sky pillar
You might need to open the door to the 8th gym in Pokémon Ruby, Sapphire and Emerald. To do this you first have to awaken Rayquaza.
you have to distory the door
Open the door and challenge the gym leader.
to open the door of the 7th gym!
In Ruby and Sapphire, you have to fight the respective legendary before the doors open.
wake up raquaza in the sky pillar
You have to win all of the other gyms then go right into it and the doors are open
ok this may sound hard but you can do it. 1.you get right in front of the door. 2.you get ready to go in. 3.walk straight into the door, and WA LAA you are in the gym!
travel up the left side of the gym and hit the red button at the top
I havn't really played it in two years, but, i think you go into the mansion next to the gym. Go to the end, and you will find the key to open the door. I think you can also find the TM earthquake. Hope I helped!!!
go tho the big mansion the find the key thare
You can find the key to unlock the door in Pokemon mansion