A recent LiDAR survey over the dense forests of Northern Thailand has identified a network of stone platforms along ancient riverbeds, identified as early 'Spirit-Boat' launch sites. These structures date back approximately 1,500 years and are believed to be the ancestral precursors to the modern Loy Krathong festival, where decorated baskets are floated on water to honor river spirits.
The survey reveals that these platforms were strategically aligned with the lunar cycle, particularly the full moon of the twelfth month. Excavations near the platforms uncovered terracotta votive offerings shaped like miniature rafts, confirming that the practice of water-based ritual offerings existed long before the introduction of Buddhism to the region. This research shifts the historical understanding of Thai water festivals from purely religious roots to much older indigenous animist traditions.