NO it is nere lilycove city but you hav to defeat magma boss in the volcano nere lavarige city
Mt. Pyre
you have to go to Mt. Pyre and stop them there first the go to the shoreline and surf up and the aquas that where standing there will be gone
near team aquas hideout in sapphire. but in emerald it is on MT. chimeny
go to lily cove city then surf right and up you must have been to mt pyre and then slateport before you can get inside though
On Mt Chimney to find it you need a magma emblem which you will get on Mt Pyre.
you are supposed to beat team aqua to get into in team aqua's hideout you are supposed to beat team aqua to get into team aqua's hideout in lilycove city
Their base is always at Lilycove, but you can find them other places (Mt. Pyre, Underwater Cavern, etc...).
That depends on your version... In Ruby, it's in a cave to the East (right) of Lilycove City, which you can only access after confronting Team Magma at Mt. Pyre. In Emerald, the Team Magma Hideout is on the Jagged pass between Lavaridge City and the summit of Mt. Chimney. The entrance will not appear until you confront Team Aqua and Team Magma at Mt. Pyre, where Mt. Pyre's matron will give you the Magma Emblem, telling you that a member of Team Magma dropped it and that it must be a key of some kind.
to get in you need to go to mt. pyre then to the path that leads to lavarage town where you get into team magma's hidout once you battle maxie and groudon goes away fly back to lilycove and you should be able to get into team aqua's hideout. you get a master ball there. but it's kind of hard to get to.
go to team magma's base after you get the magma emblem magma's base is at the route next to fiery path then beat team magma in there then go to team aqua hideout then when you talk to the team aqua members they will say that their boss is at slateport city at the ferry harbor when you go there team aquas boss will steal their submarine then when you go to team aquas hideout the guys won't be blocking anymore
After mt pyre go to mt chimney.the dudes in team agua/magmas hideout in lillycove will tell you that. After that fly back to lilly cove and swim to 128 and then find a long crevace use dive on it that will take you to the sea floor cabin.
In Emerald, an old lady in Mt. Pyre will give you Magma Emblem. After you got it, go to Judged Pass. If you bring the Magma Emblem, the Magma Hideout will appear in Judged Pass.