Pokémon Ruby and Sapphire/Mt. Chimney
Remember the entrance to the Fiery Path? Go back there and walk to the right. You will find the cable car station open. Enter it and talk to the lady. She will provide you with a car and you will be off to Mt. Chimney.
Once you are out of the car. Start climbing the mountain. You will find many grunts bullying with their Pokémon. Battle them.
|Team Aqua/Magma Grunt|
|Team Leader Archie/Maxie|
Once you beat the Team leader, he'll give up the Mt. Chimney plans. The Leader of his rival team will come and congratulate you. Walk to the machine and remove the Meteorite kept in it. Now, the path to the south of the cable car station will be open. Head down the stairs here to enter the Jagged Pass.
If you return to Mt. Chimney any time, a woman near the Cable Car station will offer Lava Cookies for 200 bucks each, which can cure all status problems. Stock up lots of them. After winning the Pokémon League, come back here to find and battle new trainers.