South Tarawa averages 450 metres across, and half the country lives there.
A line of islets joined by causeways, the lagoon on one side and the Pacific on the other: 15.76 square kilometres of land, barely three metres of elevation and more than 63,000 people. It is the capital of a country of 811 square kilometres scattered across three and a half million of ocean.
01 A strip between two waters
Tarawa atoll encloses a lagoon of some 500 square kilometres, with a maximum depth of 25 metres. The southern edge of that ring is the inhabited land: 15.76 square kilometres in all, with an average width of 450 metres.
The two sides could not be less alike. To the north lies the lagoon, shallow and calm, over pale sand. To the south is the open Pacific, which drops to 4,000 metres not far from shore. You move from one world to the other by crossing the street.
That double shoreline is the first thing to understand about the place. There is no interior here: any point in the city is a few hundred metres from two different seas, and many are less than a hundred.
02 The causeways made the city
Originally the islets were separated by shallow gaps you crossed on foot at low tide. The causeways changed that: they turned a succession of islands into one continuous strip from Betio in the south-west to Bonriki and Tanaea in the north-east.
A single main road runs along that strip, and everything else with it: the buses, the cables, the pipes and the shops. In a city 450 metres wide, the road does not cross the urban fabric; it is the urban fabric.
The names on the signs are the segments: Betio, Bairiki, Bikenibeu, Bonriki. They work as neighbourhoods, but they follow one another in line, one behind the next, with no way around them.
03 Almost five thousand people per square kilometre
The 2020 census counted 63,439 inhabitants in South Tarawa, and projections for 2026 are around 73,000. Over 15.76 square kilometres, that gives a density close to 4,900 people per square kilometre.
The figure is comparable to London's and roughly double that of Sydney or Auckland. And the genuinely usable land is smaller still: around 1,000 hectares, because part of the strip is sand, mangrove or floodable ground.
That explains how the city looks: low, continuous building on both sides of the road, small yards, very little open space and constant pressure on fresh water, which on an atoll gathers in an underground lens of limited volume.
04 Eight hundred square kilometres in three and a half million
Kiribati is 32 atolls plus one raised island, of which 21 are inhabited. Together they add up to 811.19 square kilometres of land scattered across 3,441,810 square kilometres of ocean.
The ratio is hard to picture: the country has a maritime area comparable to the whole of India and a land area smaller than many cities. More than half the population lives on Tarawa, and most of that half lives on this strip.
That is South Tarawa's real weight. It is not the country's largest city by accident: it is the only place where the cargo port, the international airport, the administration and the services of an otherwise sea-scattered territory all come together.
05 How to get around
There is only one way to move: lengthwise. Minibuses run the main road end to end and stop wherever you wave; there are no alternative routes because there is nowhere to put them.
From Betio, at the port end, to Bonriki, beside the runway, you cross the entire city in a single ride. It is worth doing at least once to watch the lagoon and the ocean alternate past the windows.
Average elevation barely exceeds three metres above sea level, and the highest point in the area is about the same. It is a simple geographical fact, but the one that best sums the place up: an entire city built on a line of sand between two oceans.
