Kashubia or Cassubia is a language area in the historic Eastern Pomerania (Pomerelia) region of northern Poland. The unofficial self-description of "capital city of Kashubia" has long been contested by Kartuzy and Kościerzyna.

Kartuzy is a town in northern Poland, located in the historic Eastern Pomerania (Pomerelia) region. It is the capital of Kartuzy County in Pomeranian Voivodeship.