UNESCO Lagoon Outer Barrier Wall

The southern section of New Caledonia's outer barrier reef is part of the UNESCO World Heritage lagoon system inscribed in 2008, and the seaward wall here is among the most dramatic in the Pacific — a continuous vertical drop from the reef crest at 2 metres to beyond 60 metres, facing the full Coral Sea. The upper 20 metres of the wall are colonised by dense aggregations of plate corals extending horizontally from the face in search of filtered light, below which gorgonians the size of small trees wave in the surge. Tuna, wahoo, and occasional hammerhead sharks cruise the blue water alongside, and the wall base holds large sea spiders, delicate wire corals, and deep-water crinoids visible to recreational divers at 40 metres on calm days. The site requires a liveaboard or long-range boat trip from Noumea.