In the Pokémon TV series, what is the name of Brock's hometown and Gym city?

Brock's hometown and Gym city in the Pokémon TV series is Pewter City. Brock is the Gym Leader there when Ash first challenges him during the Kanto journey.

The Pewter City Gym specializes in Rock-type Pokémon. Brock uses Pokémon such as Geodude and Onix in his battle with Ash. Ash earns the Boulder Badge after the contest, although the victory involves help from the Gym's circumstances rather than a simple conventional knockout.

Pewter City is one of the first major destinations Ash visits after leaving Pallet Town. Brock later travels with Ash, becoming one of the series' most enduring companions and eventually pursuing his goal of becoming a Pokémon Breeder. The city and its Gym remain strongly linked to his character.