Due to excessive sedimentation, the sea has receded about 6 km in the past 2000 years, leaving Korkai well inland today.

The Periplus says that the Pandyan kingdom extended from Comari towards the north, including Korkai, where the pearl fisheries were.

Archeologists have found ruins of chunk cutting factories, centres for split opening of pearl oysters at the site.

[citation needed] Palaeo-channels traced from the satellite imagery scenes all around Korkai indicate that the Tamiraparani river has shifted its course progressively east and south and earlier it had mixed with sea near Thoothukudi.

Interpretation of satellite imagery indicates that in the 1st and 2nd century CE, the Tamiraparani river might have flowed towards northeast from Eral, parallel to the coast and joined the sea south of Thoothukudi.