The Tamilnadu Environment Minister Siva V Meyyanathan inaugurated archaeological excavation by Tamil Nadu Open University, at Porpanaikottai, Pudukkottai.
There are reports of a fort having stood at Porpanaikottai several years ago.
The Archaeologists said the evidence found in the area dates back 1,800 years.
In 2013, the archaeology students found a culvert which is 1,800 years old.