Orientated northwest to southeast, a chain of mountains sweeps down the middle of New Caledonia's main island, Grande Terre. Four hundred kilometres long, the island is 50km to 70km across for most of its length. To the west, in the lee of the mountains, are wide, dry plains dotted with country towns, while to the east, on the windward coast, lush vegetation descends to the sea.
The island is surrounded by its legendary World Heritage–listed lagoon, though this is not Grande Terre's only 'green gold'. The other is garnierite, a silicate rich in nickel that has fueled the country's economy since its discovery in 1864.
Administratively, Grande Terre is divided into two districts, Province Nord (the North) and Province Sud (the South). Île des Pins is officially part of Province Sud.