The New Caledonia Barrier Reef is second only to Australia’s Great Barrier Reef in length, and one of the three largest reef systems in the world. It was added to the list of UNESCO World Heritage sites in 2008. Coral reefs are complex ecosystems and New Caledonia’s has an “exceptional diversity of coral and fish species” and a “continuum of habitats” from mangroves to seagrasses. The coral structures themselves are “the world’s most diverse concentration”. Threatened species such as turtles, whales and dugongs thrive here. It is also an area of great natural beauty, in the intricate formations of the reefs, the shallow lagoons they enclose and the backdrop of the island landscape. The whole reef is 1500km long and encloses a lagoon of 24,000 square km. It surrounds Grande Terre, the largest island in the group, and some of the smaller islands, its distance from the shore varying from 30km to 200km. There are natural passages through the reef including the Boulari Passage which leads to the capital Noumea. It has suffered some damage from the deposit of mining and agricultural effluent but is considered to be in a healthy state. UNESCO has initiated programmes to ensure its protection especially with the growth of tourism and the attractions of the reef and lagoons for underwater sports.