A groundbreaking study published in Nature Archaeology has utilized high-precision Thorium-230 dating to analyze anthropogenic coral structures submerged between India and Sri Lanka. The research reveals that these limestone blocks were systematically cut and placed during the late Pleistocene, suggesting a level of maritime engineering far older than previously theorized for the region.
Geological core samples indicate that the structures were originally part of a coastal defense or harbor system used by a pre-Neolithic maritime society. This discovery challenges the current timeline of urban development in South Asia and suggests that ancient communities were capable of large-scale environmental modification well before the rise of the Indus Valley Civilization.