What is the hub world town in Super Paper Mario?

The hub-world town in Super Paper Mario is Flipside.

Flipside serves as the game’s central base and is described as a town located between dimensions. From there, the player accesses the dimensional doors that lead to the game’s numbered worlds. The town contains important services, characters, and routes that support Mario’s quest to collect the Pure Hearts.

Flipside also has a mirrored counterpart called Flopside. Flopside becomes accessible later and provides a darker, reversed version of the hub-world concept. Together, the two towns emphasize the game’s central theme of shifting between perspectives and dimensions.

Toad Town is a recurring hub in other Mario and Paper Mario adventures, which makes it a plausible distractor, but it is not Super Paper Mario’s main base. Rogueport is the principal town in Paper Mario: The Thousand-Year Door, while Prism Island belongs to Paper Mario: Color Splash. The similar names and recurring locations are why the games are easy to mix up.