Fiji, meet
Timbuktu.

Fiji lands on the Niger bend in Mali. Viti Levu faces the country around Timbuktu and Gourma-Rharous, Vanua Levu the river towns of Gao and Bourem. Samoa lands in southern Niger, Apia 28 km from Tessaoua, and American Samoa and Wallis nearby, in the Zinder and Dosso regions. Tonga falls on the far south of Algeria, between Tamanrasset and the Niger border at In Guezzam; Niue on the edge of the Aïr and the Ténéré, in Niger. Tahiti lands in the desert of northern Sudan, Papeete 79 km from Ad Dabbah on the Nile. The Cook Islands face the desert of northern Chad.

To the west, Vanuatu lands in Mauritania, Luganville 2 km from Maghama on the Senegal River, and New Caledonia in the desert of the Western Sahara and Mauritania. To the east the pairs get stranger. The Marquesas land on the Rift Valley of Ethiopia, Taiohae 2 km from the antipode of Metahāra. Kiritimati faces the forest of central Congo, Pitcairn the Eastern Province of Saudi Arabia, and Easter Island the Thar Desert near Jaisalmer, in India. Tuvalu’s Funafuti lands in northern Ghana.

The misses: the Gilbert Islands of Kiribati, Tarawa included, face the Atlantic off West Africa (637 km from land). And Africa’s big cities mostly face open Pacific between the islands: Timbuktu itself is a deli sandwich, 39 km short of Fiji; Khartoum is 26 km short of the Tuamotus; Addis Ababa 80 km short of the Marquesas.

The capitals and main towns of Fiji, Samoa, American Samoa, Tonga, Vanuatu, New Caledonia, French Polynesia, the Cook Islands, Kiribati, Niue, Wallis and Futuna, Tuvalu, Pitcairn and Easter Island. On the other side, the capitals, regional capitals and cities above 100,000 across the Sahara, the Sahel and the Horn of Africa, with Arabia and India’s Thar, each listed if its other slice lands within 50 km of one of these islands, or it is a capital or a city of a million. Exact means land opposite land at the town’s own point; where the other slice would get wet, the table gives the nearest spot from which an exact sandwich is possible.

No two towns here are within a kilometre of each other’s antipode, though some come close: Luganville and Maghama, and Taiohae and Metahāra, are about two kilometres apart. Every island town in the first table is exact.

A sandwich’s elevation bonus is the height of one end plus the height of the other (Sandwich Law § 1.4). The Board scores it the way the map shows it: from the average height of the ground over cells about 20 km across, so every spot in a cell scores the same and you only need to be in the right cell, not on the summit. These are the corridor’s best cells, one per area, each with dry land at both ends.

1. +1,280 m1 km from Taiohae (Marquesas Islands, French Polynesia)cell average 200 m2 km from Metahāra (Oromiya, Ethiopia)cell average 1,080 m
2. +1,120 m15 km from Gataivai (Palauli, Samoa)cell average 680 m34 km from Mayahi (Maradi Region, Niger)cell average 440 m
3. +800 m23 km from Vatukoula (Western, Fiji)cell average 520 m93 km from Gourma Rharous (Tombouctou, Mali)cell average 280 m
4. +720 m4 km from Lauli’i (Samoa)cell average 280 m35 km from Takiéta (Zinder Region, Niger)cell average 440 m
5. +720 m26 km from Bouloupari (South Province, New Caledonia)cell average 520 m94 km from Choum (Adrar, Mauritania)cell average 200 m

The best cell pairs the ridge above Taiohae on Nuku Hiva with the Ethiopian Rift near Metahāra, at an average of 1,080 m: the Marquesas are the one island group here whose twin is in the highlands.

The window. Both slices must go down within five minutes of the same UTC instant (Sandwich Law § 2.1). The sandwich lobby holds you to it: when the first slice lands, the other side has five minutes.

The clocks. The date line runs through this corridor. Fiji is 12 hours ahead of Mali, Samoa and Tonga 12 hours ahead of Niger and Algeria, and Kiritimati 12 hours ahead of central Congo, so at noon UTC it is already tomorrow on those islands. Tahiti is 12 hours behind Sudan, and the Marquesas 12½ hours behind Ethiopia: the same noon is still today there. Agree the minute in UTC and let the calendars sort themselves out.

The light. Two exactly opposite points are never in daylight together: sunrise at one end is sunset at the other. The atmosphere bends a little sunlight over the horizon, so twice a day, on a clear flat horizon, the sun is up at both ends at once for about seven to eight minutes. Put the bread down then and both photographs get golden light, one at dusk and one at dawn.

The seasons. Opposite. The Sahel’s rains come in the northern summer, which is the islands’ dry season; the Saharan summer is fiercely hot.

The geometry is the easy part; the hard part is a person at the other end, and the site does not match strangers. Many of the African twins lie in parts of Mali, Niger, Chad, Burkina Faso and Sudan that are covered by travel warnings: check your government’s advice before you plan anything, and do not ask anyone to put themselves at risk for bread. Mauritania, Ethiopia, Ghana and the Thar Desert are easier places to start.

Then open an attempt in the sandwich lobby. It gives you a code and a link to send through whatever channel you already share, shows both slices when they arrive, and runs the five-minute window. The desert ends are remote: go with people who know the ground, and carry water. The exact grade allows a kilometre of slack, which is usually enough to find somewhere you are allowed to stand.

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