Beat Crasher Wake in Pastoria city gym.His Pokemon are Gyarados(use electric and rock moves),Quagsire(use grass moves),and Floatzel(use grass and electric).Beat him and get the Fen badge.
The fifth gym leader in Pokemon platinum is crasher wake but you get the fourth badge.
Talk to the poketech guy in jublife city who is inside the poketech building. If you have won the fourth gym badge, he will give you the marking map app.
Beat the gym
victory road north of sunyshore city but you have to have the sunyshore gym badge to get there
Fourth Badge is Morty - the Ghost-type Gym leader. He's in Ecruteak City - boasting a team of a Gastly, 2 Haunters and a Gengar. You'll have to go to Burned Tower and awaken the legendary dogs to be able to face him.
keep playing, no stuff... xD
The fifth gym leader in Pokemon platinum is crasher wake but you get the fourth badge.
You need to have beaten Maylene (the fourth gym leader who is in Veilstone) to be able to use fly.
Hearthome's badge
the relic badge in hearthome city
the fourth gym is in celadon city at the bottom left of the city. the gym leader is erika. the badge is called the rainbow badge
you get the coal badge after defeating Roark in eterna city
island? the fourth badge is in celadon
Talk to the poketech guy in jublife city who is inside the poketech building. If you have won the fourth gym badge, he will give you the marking map app.
if you are looking for the third gym badge i suggest Veilstone city.
Pastoria Town
in the 1st gym badge