An internationally recognized hot spot for the planetary biodiversity, the 4,970sqmi (8,000km²) of coral reefs and the 14,540sqmi (23,400km²) of lagoons of New Caledonia represent one of the most varied and extensive reef complexes in the world. The almost 994mi (1,600km) long coral reef which delimits and protects the Caledonian lagoons is the longest continuous barrier and the second largest barrier with, locally, a very rare phenomenon of double or triple barrier reef of which less than 10 cases can be observed worldwide.