In Ruby and Sapphire, you have to fight the respective legendary before the doors open.
I don't think you can, in emerald you need the nationaldex and POW! it's open but in ruby and sapphire you can't.
by getting a life
well they are secret bases but you need to teach one of ur Pokemon secret power(tm43), and u can get it in slateport city at the open market!(In Pokemon Sapphire).
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.
Go to the sealed chamber on route 134 and be sure to have a Pokemon with dig, and have WAILORD and RELICANTH in your party
Go to its ruins in Northern dewford route,turn aroud the cave(Hope you know how to open it),a hole will appear.There is Rejice.
Go in the sealed chamber on the route west of pacifidlog town to find it you need the HM Dive. Solve the braille puzzle then the rock will open.
trade
bush staduim opened in may 12 1966
ewan q
Yes
The elite four will open and they will be stronger and you can now trade with ruby, sapphire and emerald.
Strawberry Bush -Euonymus Americanis
cut open the door
April 5, 1975.
In Ruby and Sapphire, you have to fight the respective legendary before the doors open.