Pewter Gym is a location in the Pokémon video game series, specifically found in the Kanto region. It is known for being the first gym that players encounter in their journey. The gym specializes in Rock-type Pokémon, and its leader is Brock, who is known for his expertise in this type of Pokémon. In Pewter Gym, trainers must battle Brock to earn the Boulder Badge, which is essential for progressing in the game. The gym features a simple design, with rocky terrain and a few trainers to challenge before facing Brock. Defeating him allows players to advance to other gyms and continue their quest.