The Grand Reef of Koné is one of the fringing reefs which surround Grande-Terre, the main island of New Caledonia. It belongs to the low-energy reefs which run along the west coast of the island and are protected from the swell by the barrier reef. With a width inferior to 1968ft (600m), it consists of two reef units attached to the Pleistocene (from -2.58 million years to -11,700 years) for the deepest one and to the Holocene (last 10,000 years ) for the upper one.