Marine archaeologists exploring the Arafura Sea have mapped a massive system of stone-walled corridors and enclosures submerged in twenty meters of water. These structures, identified using 3D robotic sonar, are believed to be sophisticated ritualistic fish traps built by early Aboriginal populations approximately 10,000 years ago, before post-glacial sea-level rises inundated the Sahul shelf.
Unlike functional fish traps found elsewhere, these stone arrays follow a complex geometric pattern that suggests a symbolic or ceremonial purpose. Researchers suggest that these "water labyrinths" were used for communal gatherings and spiritual rites linked to the arrival of seasonal migrations. This discovery provides the first physical evidence of permanent, large-scale stone construction on the now-sunken coastal plains of northern Australia.