Archaeologists working in the Kapuas River Basin of Kalimantan have discovered the post-hole foundations of what appear to be the earliest known 'spirit houses' (rumah panyai) dedicated to harvest deities. These structures predate previously known ritual sites in the region by nearly 800 years, offering a new timeline for the evolution of the Gawai Dayak harvest festival. The site yielded carbonized rice grains and charred bamboo used in traditional ritual cooking.
The orientation of the structures suggests they were aligned with the midsummer lunar cycle, a key component of ancestral Dayak agricultural calendars. Cultural heritage experts state that the discovery validates oral traditions that have long claimed the festival's roots stretched back to the early Iron Age. This excavation provides the first tangible link between prehistoric agricultural success and the formalization of communal thanksgiving rites in Southeast Asia.