The 8th and last gym is in Sunyshore City.
go to the Pokemon league north of sunyshore
where can i find the second gym in Pokemon platinum
You can use the GTS in Pokemon Platinum after you get the first gym badge from the Oreburgh City gym.
after beating the 8th gym leader go to the beach and the lady will give you the HM 7 waterfall
volkner
The 8th and last gym is in Sunyshore City.
sunnyshore city
go to the Pokemon league north of sunyshore
Defeat the 8th
The 8th gym leader in Pokemon Light Platinum is located in a city called Lauren. You can find the gym leader in the Lauren League Headquarters.
beat the 8th gym and then go up and there is a person from hoen and also gym leader will give it to you
the 8th gym is closed because you have to beat all other 7 gyms and then it will be open p.s. the 8th gym leader is giovonni
After You Defeat All The Gyms Jasmine The 8th Gym Leader Of Johto Should Give It To You.
where can i find the second gym in Pokemon platinum
to get to the 8 gym first you have to catch/beat palkia/dialga(or girantina in Pokemon platinum)
The fifth gym leader in Pokemon platinum is crasher wake but you get the fourth badge.