Muju lay near the frontier between Baekje and Silla. Muju County’s official guide says that Mupung-myeon east of Rajetongmun retains speech and customs associated with the Gyeongsang region, while Seolcheon-myeon to the west reflects Jeolla and Chungcheong traditions.
Administrative borders changed long ago, but traces of the old frontier remain in local language and culture. These are regional tendencies, not a claim that every resident speaks identically.