Where is the 3rd gym in pokemoon dimand?

In Pokémon Diamond, the third gym is located in Veilstone City. The gym leader is Maylene, who specializes in Fighting-type Pokémon. To reach the gym, players must first navigate through the city and complete various tasks, including defeating Team Galactic in their headquarters nearby. Once inside the gym, players will face trainers and puzzles that revolve around the Fighting-type theme.