In gym number seven
the seventh gym badge snowpoint gym
It's located inside Pokemon mansion which can be found near the seventh gym.
In Diamond, Pearl and Platinum 7th gym is in Snowpoint Town.
You have to beat the gym leader, Pryce, in Mahogany City.
Fight the seventh gym on Cinnabar Island. Then fight the eighth gym at Virirdian City.
The last gym badge is in viridian city for Kanto. For Johto it is in Blackthorn city.
You get the seventh gym badge after you defeat the snowpoint gym leader Candice she carrys the following Pokemon .... Snover, Sneasel, Medicham and Abomasnow and if your wondering how i know so much i am the Pokemon champion so you can send me questions anytime My name on wikianswers is ILovePokemon GOOD LUCK ON YOUR GYM BATTLE!!!!!!
After you beat the gym, you must leave, heal ur pokemon, then go back and talk to the leader and she should give you the badge
Directly to the right of the city with the fourth badge.
You get the badge there and the TM for Shadowball I think.
its in cinnabar island, south of pallet town use surf to get there it is a fire gym
You have to fight the fire gym leader which is located at cinnabar island. i dont know his name though