Keeladi is a significant archaeological settlement site located near the town of Keezhadi in the Sivaganga district of Tamil Nadu, situated on the banks of the Vaigai River, about 12 km southeast of Madurai. It is a key site for understanding the Sangam Age culture of ancient Tamil Nadu.
The excavation originated from an archaeological study by the Archaeological Survey of India (ASI) in 2013-14 along the Vaigai river valley. The findings solved the problem of establishing a definitive timeline for the Sangam period, as radiocarbon dating of a sample from the fourth phase of excavation, conducted by the Tamil Nadu State Department of Archaeology (TNSDA), traced the settlement's origin to 580 BCE. This date pushes the timeline of the Sangam Age back by about 300 years from the previously accepted 3rd century BCE.
The site works as a window into an ancient urban civilization, often referred to as the Vaigai Valley Civilisation. Excavations have revealed over 18,000 antiquities, including sophisticated brick structures, ring-wells, and evidence of industrial activity like weaving and metallurgy. A crucial finding is the discovery of potsherds inscribed with Tamil-Brahmi script, which, being dated to the 6th century BCE, suggests a high level of literacy and pushes back the script's known date. This evidence connects Keeladi to the concept of India's second urbanisation, as it was contemporary with the urban developments in the Gangetic plains. Furthermore, graffiti symbols found on the pottery bear resemblance to signs from the Indus Valley Civilisation, suggesting a potential link between the Indus script and the Brahmi script. The excavation phases were initially led by the ASI (2014-2016) and subsequently by the TNSDA (from 2017-2018 onwards), with the latter's report establishing the new, earlier dating.