by having strong Pokemon
Surf right from Lilycove after beating the team Magmas Base
just walk in front of the stone when you have there emblem
You don't get it in Sapphire, only Ruby and Emerald
U have to go to mount pyre
all you have to do it use surf to continue north to the cave opening, go in and beat all the trainers, yata yata (note:this is also where you get the masterball)
near the cavern of team aqua! rout 128!
You use it to get groundon activated
you go to sootopolis city and then find team magmas base and after you have found and gone to the boss and beat him then go to the orgion cave and get the leagendariey Pokemon for you groudon then you go to the gym and og pass the cracked ice floor look up on youtube and then fight and done thanks for listening mjf139
you only have to beat the elite 4 on Pokemon fire red not ruby
you play it
Pokemon Ruby in the Cave of Origin after getting your seventh badge. AT THE UNDER WATER CAVE A.K.A.TEAM MAGMAS HIDEOUT
i think you can get one in team magmas hideout in lilycove city but im not sure. good luck;)