Go to Jubilife City (make sure u have a Pokemon with surf on your team) and go west. You'll come to an area where u can surf. Surf and you'll come to the next town (Canalave City) with a gym in it.
It's back in Hearthome city.
The 8th Badge in Pokemon Diamond is called The Beacon Badge.
THE 5TH GYM LEADER IS IN HEARTHOME CITY. HER NAME IS FANTINA.You must return to Hearthome, where Fantina will be there to accept your challenge for the 5th badge.
the poketch marking map can be obtained by the poketch president after getting the 5th or 7th badge
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In Diamond, Badge 5 can be gotten by defeating Fantina in her Gym in Hearthome City.
hearthome city
Hearthome
Hearthome City.
The lose of dignaty you had
the seventh gym badge snowpoint gym
It is the balance badge where you fight Norman(your father) in Petalburg City .