The Rayo Duo festival and the spatial meaning of Rumah Godang in the inhabited culture of the Sentajo Community, Riau, Indonesia

Abstract Koto Sentajo in Riau, Indonesia, offers a unique example of a culture where traditional architecture and customary practices remain central to daily life. As a living settlement shaped by matrilineal kinship and indigenous governance, its core spatial elements, the Rumah Godang (traditional house), mosque, and Balai Adat (customary hall), function as anchors of cultural continuity. This study addresses the challenge of sustaining vernacular heritage in the face of modernisation by examining how traditions are maintained through communal rituals and spatial organisation. Using ethnographic methods, the research documents how the Rayo Duo festival (the second day of Eid al-Fitr) mobilises community members across generations to reactivate customary roles and restore ancestral houses. Findings reveal that cultural sustainability in Koto Sentajo depends on integrating social structure, spatial form, and philosophical values, embodied in the concepts of Tungku Tigo Sajorangan and Tali Tigo Sapilin. The study concludes that the endurance of the Rumah Godang is not merely architectural but rooted in living practices, making Koto Sentajo a model of community-led conservation and indigenous resilience.