<![CDATA[This study aimed to formulate the GRANDLINE learning model as an adventure-based pedagogical innovation designed to enhance student engagement and learner autonomy in the context of 21st-century learning demands. Employing a library research design, this study synthesized theories of constructivism, experiential learning, adventure education, collaborative learning, student engagement, and self-regulated learning. The analysis revealed that the GRANDLINE model consisting of Goal Setting, Route Planning, Adventure, Navigation, Discovery, Logbook Reflection, Integration, Narration, and Evaluation was theoretically effective in fostering active participation, strategic learning behavior, reflective thinking, and independent regulation of learning. The early stages (Goal Setting and Route Planning) strengthened student agency, while the Adventure and Navigation stages promoted experiential learning and adaptive scaffolding. Discovery and Logbook Reflection encouraged metacognition, whereas Integration and Narration facilitated deeper conceptual understanding and authentic knowledge application. The findings indicated that GRANDLINE addressed existing gaps in the literature, including the lack of classroom-based adventure learning models, the limited integration of engagement and autonomy within a single pedagogical framework, and the need for structured reflection elements. The study concluded that the GRANDLINE model has strong potential to enrich instructional practices and may be further validated through empirical classroom implementation.]]>
