Pewter City Gym is a location in the Pokémon video game series, specifically found in Kanto. 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. Inside the gym, trainers face challenges that test their skills and strategy against Rock-type Pokémon. Defeating Brock grants players the Boulder Badge, which is essential for progressing in the game. The gym also serves as a place for trainers to learn about Pokémon battles and improve their skills.