In the context of the administrative merger of Tien Giang and Dong Thap provinces, developing a destination brand for the newly established entity has become imperative in order to create a unified identity that both inherits existing values and asserts competitive positioning within the tourism landscape of Southern Vietnam. This study adopts a qualitative research design with 15 in-depth interviews among three stakeholder groups, including tourists, experts, and tourism enterprises. The data were thematically analyzed, guided by the analytical framework of destination branding and destination brand equity. Findings indicate that differences in cultural identity and product specialization between the two provinces generate challenges in harmonizing brand images, yet simultaneously open opportunities to build a comprehensive destination brand. The major challenge lies in the risk of diluted or overlapping identities, whereas the opportunity emerges from the possibility of creating a coherent destination narrative. This narrative serves as a seamless journey “from gateway to core,” structured around four pillars: river landscapes, orchard-based experiences, lotus-centered ecotourism, and Southern Vietnamese cultural heritage. Theoretically, this study contributes to the literature by situating destination brand building within the context of administrative restructuring, a phenomenon rarely examined in tourism branding research. Practically, the study provides strategic insights for policymakers, marketers, and local stakeholders in designing communication campaigns and product portfolios; thereby, it helps enhance the competitive and sustainable development of the new Dong Thap destination brand.