Twinleaf Town is located in the Sinnoh region, it's a small town with only four houses and a small little pond at the bottom. In all, you can only catch four different types of Pokémon here, all of which are water types. The bottom right house is where you and your mom live. The top left house is where your best friend and rival live. You'll only come here a few times, mostly at the beginning of the game.