You can only get to it when kyogre and groudon are fighting you are not allowed back in ever again after that
In the cave of origin and marine cave.
There is no Pokemon in the Cave of Origin in Pokemon Emerald.
the cave of origin is only in ruby and sapphire and emerald.
A desert I think
KYOGRE!
Nothing exciting happens there on emerald.
in sootopolis city
The cool thing about emerald is that you can get 2 kyogres in the game: One in the cave of origin the other in marine cave.
In Sootopolis City, at the side where the PokeMart is. Go up, and you'll find Cave of Origin
In the cave of origin which is in sootoplis city.
it is inside the cave of origin
To open the Cave of Origin in Pokémon Emerald, you must first go underwater to the Seafloor Cavern. There you must defeat Archie.