New LiDAR mapping in the Red River Delta has identified a previously unknown two-kilometer-long causeway connecting a major Dong Son citadel to a ceremonial mountain peak. The path is perfectly aligned with the sunrise during the spring planting season.
Excavations along the causeway revealed bronze bells and drums buried at regular intervals, which experts believe were used during the "Rice-Spirit" processions to call for rain. These findings suggest that Dong Son society possessed a highly organized system of state-sponsored agricultural festivals. This mapping project rewrites our understanding of ancient Vietnamese landscape architecture and the deep roots of modern lunar new year and harvest celebrations in the region.