Excavations in the Pearl River Delta have brought to light "malachite-inscribed" turtle shells belonging to the ancient Nanyue kingdom. Dated to approximately 2,200 years ago, these artifacts were central to the "River-Mirroring" festivals, where participants used the reflective properties of water and shell to communicate with ancestral spirits during the summer solstice.
The inscriptions contain references to "The Great Mirror of the South," a metaphorical description of the delta waters. This find highlights the unique cultural synthesis of the Nanyue people and the sophisticated ritual logistics required to coordinate large-scale water-based celebrations across the region's vast network of estuaries, predating more modern lunar-based festivals in the area.