You through pastoria city past the guards and you will be there.!
How Do U Get To The 7th Gym On Pokemon Platinum?
Walk along the snow on mt cornet
Beat the jim leader then he will give it to you. Be patient I know you want it.
You walk through Mt. Coronet walk along all of the snow until you reach a small forest then you go to the right and you're in the city shaped as a giant snowflake,Snowpoint City.
Ive beaten the seventh gym leader! All you need to do is knock out the snowballs in the middle row
Wen you first walk in go to the end of the snow then turn right then go down then turn right into snow then go down then turn left to the other side then go north then turn right then go north then left then go down and back to the second floor then go to the small thing of snow then go down then go north then turn right then go back to the entrance turn left then go all the way north then turn right then go down and turn right then go to the stairs at the beginning here the fun part go down the ice and face her