The Tropic of Capricorn is the southern twin of the Tropic of Cancer, sitting the same distance from the equator and marking the furthest south the sun ever stands directly overhead. That happens on the December solstice, and only on that day.
Geometrically it mirrors Cancer exactly. Geographically the two have almost nothing in common. Cancer runs through seventeen countries; Capricorn manages ten, because the southern hemisphere at this latitude is mostly ocean. Between Madagascar and the Western Australian coast lie about 6,700 km of uninterrupted Indian Ocean, and the Pacific leg from Queensland to Chile is twice that again.
What land there is tends to be spectacular. The line crosses the Atacama, the driest non-polar desert on Earth, then the Kalahari, then the Australian outback, and it passes about 12 km north of the centre of São Paulo on the way.
Worked out by intersecting the line with national borders, so the order is the order you’d meet them tracing the line west to east. Tap any row to fly the map to that crossing.
| # | Country | Enters and leaves | Distance |
|---|---|---|---|
| 1 | 330 km | ||
| 2 | 590 km | ||
| 3 | 590 km | ||
| 4 | 1,100 km | ||
| 5 | 560 km | ||
| 6 | 750 km | ||
| 7 | 440 km | ||
| 8 | 390 km | ||
| 9 | 410 km | ||
| 10 | 3,800 km |
Latitudes here use the J2000.0 axial tilt of 23.4394°. The 2026 figure is nearer 23.4359°, which puts the real line about 390 m nearer the equator than the coordinates above, and it keeps shifting by roughly 14.5 m a year. No crossing changes hands over that distance.
Start in Chile on the Pacific coast north of Antofagasta and head east: Argentina, Paraguay, Brazil. The line leaves South America near Ubatuba and doesn't touch land again for roughly 6,000 km until the Namibian coast near Swakopmund.
Then Namibia, Botswana, South Africa, Mozambique in quick succession, a short gap across the Mozambique Channel, and Madagascar. After that the long one: the Indian Ocean crossing to Western Australia, where the line comes ashore near Carnarvon and runs 3,800 km east to the Queensland coast at Rockhampton. That single Australian crossing is longer than everything the line does in Africa put together.
The Pacific leg is the emptiest stretch on this line by a wide margin. From the Queensland coast to Chile is roughly 14,000 km of water with barely an island on it. New Caledonia sits just north, French Polynesia well to the east, and in between, nothing.
Same latitude, same solar geometry, wildly different climate, and the reason is water. Oceans cover roughly 80% of the southern hemisphere at this latitude against about 60% in the north, and water moderates everything. Summers are milder, winters less severe, and the subtropical high-pressure belt sits over sea for most of its circuit rather than baking continental interiors.
The deserts that do form here are coastal and strange. The Atacama is dry because the cold Humboldt Current kills convection offshore and the Andes block moisture from the Amazon, which together produce places where no rainfall has ever been recorded. The Namib works the same way with the Benguela Current, so both run down to the beach and both get fog with no rain behind it.
There's also a quirk of timing. Earth reaches perihelion, its closest approach to the sun, in early January, three weeks after the December solstice, so southern summers get about 7% more sunlight than northern ones. The oceans soak most of it up.
Rockhampton in Queensland has a spire marking the line at the southern edge of town, and calls itself the Beef Capital of Australia, which is unrelated but worth knowing. Alice Springs sits about 30 km south of the line, and the marker north of town on the Stuart Highway is one of the most photographed road stops in the Northern Territory.
São Paulo is the big one. The city centre at 23.55°S falls just outside the tropics by about 12 km, and the line crosses the northern districts of the municipality. Of all the cities sitting on any of these seven lines, São Paulo is comfortably the largest, and almost nobody there thinks of it as a tropical city.
Elsewhere the line keeps to provincial towns. It comes ashore in Chile about 25 km north of Antofagasta, crosses the Kalahari in Botswana with nothing on it for hundreds of kilometres, and South Africa marks it with a sign on the N1 in Limpopo, 50-odd km north of Polokwane.
And the markers keep going slightly wrong. The tropic drifts towards the equator by about 14.5 metres a year as the axial tilt reduces, so a monument set precisely in 1980 is now around 650 m off. Rockhampton's spire has the problem. So does the one at Alice Springs.
The catch is resolution. Ten thousand points for the whole world means smoothed coastlines, islands that vanish entirely, and entry points that can sit 20 or 30 km from where a surveyor would put them, which is why distances are rounded to the nearest 10 km. The order of the countries is solid. The last digit of any single figure isn't. Crossings the data is too coarse to hold get named under the table rather than quietly folded in.