Funafuti is where Charles Darwin was proved right. Between 1896 and 1898 the Royal Society drilled into this atoll to test his claim that a coral ring is the crown of a volcano sinking beneath it — and at 340 metres the bit was still cutting through coral, exactly as a subsiding mountain would require. The shaft is still on Fongafale, kept as Te Vili o Tavita, David's Drill, named for the geologist who led the second attempt. What the coral built is a ring of some 29 islets around Te Namo, a lagoon 24.5 kilometres long and deep enough that an American fleet anchored inside it in 1943; the land itself adds up to 2.4 square kilometres. Fongafale, the main islet and the capital of Tuvalu, runs 12 kilometres end to end and narrows in places to about ten metres.
Walk that strip and the Pacific breaks on one side while the lagoon lies flat on the other, both at once. The airstrip American crews cut across the island's widest point in 1943 is now the town square: planeless most days, it fills at dusk with kites, motorbikes and volleyball. Boats cross the lagoon to uninhabited islets — Tepuka, Fualopa, Vasafua — empty but for seabirds. The sea here is climbing faster than the global average. Nothing in Tuvalu stands more than about 4.6 metres above it, the coral underfoot is porous, and so the biggest tides push seawater up through the ground itself, spreading pools across the runway without a drop of rain. The country's answer is to build higher: a platform of dredged sand finished in 2023 raised nearly eight hectares of Fongafale above the projections for 2100, and more is under construction. Since 2025 an Australian treaty has also offered 280 Tuvaluans a year permanent residency.