Fish River Canyon is the largest canyon in Africa, 160 kilometres long and close to 550 metres deep in southern Namibia, and for most of the year there is no river in it. The Fish floods after the summer rains and then shrinks back, so through the dry months it reads from above as a chain of still pools rather than a river. What those pools do is loop. They swing hard around one rock spur after another, and that, not the depth, is the thing you end up staring at from the rim. The Nama have an answer for it. A giant serpent called Koutein Kooru took their livestock until hunters cornered it with dogs and torches, and the canyon is the furrow it tore across the plateau while it died. An unfenced path runs the edge from lookout to lookout, and every few hundred metres the angle shifts and another set of bends comes into line.
The hour to be above Hobas is the early one, before the sun floods the gorge, when you can work your eyes slowly along the terraces just under the rim. Hartmann's mountain zebra and klipspringer pick their way across slopes that look sheer from the top, reading as specks against the rock. At the other end of the day the quiver trees go white-gold on their forking trunks, giant aloes rather than trees, whose soft branches San hunters hollowed out to carry arrows. The way down starts at Hikers' Viewpoint with a chain-assisted scramble over the first steep hundred metres, and then it is some 85 kilometres of sand, boulder-hopping and river crossings over four or five days. You carry everything, sleep on sandbanks and drink from those pools. The route is walkable only in the cooler half of the year: summer on the floor passes 45 degrees and the slot below floods. It ends at ǀAi-ǀAis, burning water in Nama, where sulphurous springs come up at about sixty degrees through the same shattered rock that let the canyon open. After four days of cold pools, you get into that.