The large pigeon island is edged by a coral reef which is about 200 m long and 100 m wide and the small pigeon island is enclosed by rocky islets. The national park also boasts of the best remaining coral reefs of Sri Lanka. 100 species of corals and 300 coral reef fishes are recorded in the vicinity. Sea turtles such as Hawksbill turtle, Green turtle and Olive Ridley migrate the coral reef whereas shallow coral areas harbours Juvenile and adult Black-tip reef sharks. Apart from these, you are privileged to experience scuba diving and snorkeling which enables you to step into the underwater paradise.