The Congo is the interior's highway. Below Pool Malebo, it ends.
350 kilometres of rapids, 270 metres of drop, the largest waterfall on Earth by volume, if rapids count. Stanley named them for Livingstone, who never saw this river. The wildest he'd ever seen, its roar an express train in a rock tunnel.
The interior's cargo crossed that wall. First by hand: a portage often fatal. Then by rail. Leopold's Congo Free State built the Matadi-Kinshasa line, 1890-1898, 366 km. Official dead: 1,932, 1,800 Africans and 132 Europeans; the real count higher. In 1892, of 7,000 recruited, 3,500 died or fled. Barbados recruits forced off the boats at gunpoint; seven died.
The falls never stopped the extraction; they only changed who carried it. Rebuilt in the 1920s on 1,067 millimetres, the gauge both banks share today, the gauge of the bridge still not built.
Now the wall is measured for power. Grand Inga: seven stations in the falls, 40 to 70 gigawatts, the largest power station on Earth, in the rapids that stopped the ships. The river that ends the road may light both banks.
I am still learning to carry my own weight without laying it on someone else's back.