Watson the gym leader of mauvile city will give it to you.
its in the mewtwo mansion in the basement
you find the basement key in the underground path
The key is hidden in the basement of Pokemon Mansion which is located on Cinnibar Island.
Ruby & Sapphire Key
It is in the Pokemon House (in the basement), left of Cinnabar Island.
if you get the yellow key and do the puzzle you should get it (you are talking about cool basement escape arnt you?)
The secret key is hidden in the basement of Pokemon Mansion which is located on Cinnibar Island.
its on an island that opens after you beat the elite four. to get there just surf a litle east of pacifilog town stay at the top and youll find a path the the sky tower
The only way you can get a Thunderstone in Pokemon Ruby is by finding a Yellow Shard and trading it for a Thunderstone in the Hunter's houe, just off Mosdeep city. These shards are found when searching the ocean floor with a Pokemon who knows Dive. Of course, you can get a friend to attach a Thunderstone to one of their Pokemon on FireRed or LeafGreen and trade it to your Ruby version.Another solutionThere is also a thunderstone in the basement you just have to fing it. Mauville. He will give you the BASEMENT KEY. Surf off to the right of route 110. Go in the cave and you'll enter the basement. At the end of the basement theres a pokeball. Inside is a thunderstone.
The basement key can be found in the room with projector. The projector shows animals that correspond with pictures of animals in the room that can be pressed. Press them in the correct order to reveal the basement key.
the key is in the basement
No Where!