Kurusadai Islands: (20 kms.) To the west of Pamban bridge and between the mainland and the island is a vast area surrounded by a chain of coral reefs. It can be reached from Mandapam by a boat. The shallow waters of this place sustain remarkable variety of marine life such as, star fish, algae, sea cucumbers, crabs, sponges and sea cow. It is a paradise for biologists who can study the flora and fauna of this region.