The Cœur de Voh is a clearing about four hectares across in the mangrove on the northwest coast of Grande Terre, the main island of New Caledonia, and it is shaped almost exactly like a heart. Nobody made it. The ground there turns too salty for trees, leaving a bare patch called a tanne, and the channels that drain the swamp happen to draw the outline. Nobody standing on it can see it, either. Down at sea level the mangrove is a flat grey-green tangle at the edge of the lagoon, and the shape does not register at all. It became famous by accident: Yann Arthus-Bertrand photographed it from a helicopter in 1990, the picture went on the cover of Earth from Above, and the book sold in the millions.
There are two ways to get the height. A marked trail climbs the ridge of Mont Katépahie behind the town, 7.7 kilometres there and back for 340 metres of ascent, with almost no shade on it, and the ridge turns fierce by midday. The heart does not arrive all at once. It assembles as you climb, and only from the picnic plateau at the top does the mangrove below sort itself into a clean figure against the pale water. The other way is the air. Small planes and ultralights go up from the local strip and bank low over the clearing, the one angle that gives you the outline as crisp as the photograph. From up there it is only part of what you see. The Gatope reef lies beside it, a blue hole sits in the shallows as a dark disc, and the whole lagoon is held in by a barrier reef that runs almost the entire way around the island. The shape itself is softening. A ring of tall red mangrove still traces the outline, but low grey scrub has spread across the middle, where the sea now reaches only on the highest tides. The heart you climb to is already greener and blurrier than the one on the cover.