You must go to the hidden cavern that is located in Mossdeep. Once inside the cavern beat all the Pokémon inside and also beat Team Magma leader. Then go to the cave of origin in Sootopolis City and catch Groudon. Once you catch Groudon the gym door will unlock.
you need to look in the trash cans. one of them might have a switch
its impossible to get in there unless you have cheats. but there wouldn't be anything in there
The sapphire is on Six Island. You need a Pokemon to use cut on the dotted door of the cave.
Tou have to turn on all of the switches and then go to where you started (the entance door) and then you take the pointy arrow pad on the left and fite the gym leader
Fight Wally who is by the door
behind the door is leaf green u enter the Pokemon leaf green world
its a building on sixth island that contains the sapphire. to get in it, use the HM cut on the door to slice the it open. then fall down the hole u see wen u enter then go... up, left, right, and down. and there is the sapphire. hoped this helped!!! bye:)
Forever
In the toliet
In the basement of the Pokemon mansion on cinnaber.
How do you unlock the door in the old man's house who lives on mossdeep city on Pokemon Ruby
I think with cut!!!