Out in the middle of the Sahara Desert, in the Algeria's southeast, a three-metre-long oblong rock that resembles a massive grand piano lies balanced just above the ground on some smaller stones. Into its upper surface have been ground some 30 depressions, while three much deeper cavities have been etched into its end.
The rock is called Toneynek tan Korombi, or the Stone of Korombi. It's a rock gong through which local people believe the spirits communicate, divining the future, telling of war, when to expect rains and harvests, and the whereabouts of lost livestock. Although no-one knows who made it, the elders still know how to operate it and interpret its messages. "When the stone speaks harshly we expect trouble, but soft reverberations mean peace and gentle rain," says my Tuareg guide Kilikili.
I was in the remote gorges of Algeria's Tassili n'Ajjer (the Ajjer Plateau) as part of an expedition to record for posterity some of Africa's largest and finest examples of rock engravings. In 2000, I had been inspired by a drawing by the French archaeologist Henri Lhote to visit a site in the bed of a wadi--a seasonally dry river--known as Oued Djerat. The site contained 14 magnificent engravings of giraffes, three of which measured more than nine metres long.
Gazing at the engravings, I'd been fascinated by their size and anatomical accuracy, and wondered how preliterate peoples could have created such masterpieces. They were clearly executed by one or more master craftsmen, whose counterparts today would surely be among the greatest artists of our time.
However, I was worried by their eroded state, so I left determined to return and create a single photographic image of this vast 100-square-metre panel--almost certainly the largest rock art image anywhere on the African continent. Not only was I keen to record it for posterity, but this was a prehistoric image of global importance, and it was important for people to be able to see the whole image for the first time.
Kilikili had excited me further with tales of even larger engravings of giraffe in a valley farther into the massif that had never been visited by Europeans.
Two years after my previous visit, I returned to Algeria with Alec Campbell, retired director of Botswana's National Museum and Art Gallery, and two other colleagues. We set out from Tamanrasset heading northeast and travelled for some 650 kilometres through roadless rocky desert to a little town, Illizi, just north of the great Tassili n' Ajjer. From here, it was another SO kilometres to the mouth of the Oued Djerat, where we continued our journey by camel up the rocky gorge into the heart of the plateau.
During the day, we gasped in the heat as the sun beat off the rocks. At night, we huddled in our bags against the cold. And all the time, the camels stank.
The rocky walls soared to a height of more than 200 metres, shimmering in shades of ochre, and a hot sun cast wavering shadows below the camels. We passed a Tuareg encampment tucked below the cliff, a thin plastic sheet over a pole frame, three women, some children, camels and perhaps 100 goats.
Long before writing was invented, Stone Age hunter-gatherers chipped and polished engravings in rock surfaces and painted with fingers or brushes using pigments made of ochre, clays and charcoal, possibly bound together by blood, plant juices and egg white.
Of all the continents, Africa has the greatest diversity of rock art. Unlike the prehistoric paintings of southern France and Spain, which are found deep within caves, Africa's ten million or so images are found mostly on exposed rocks and on the walls and roofs of cliff shelters, where they are at the mercy of the wind and rain, the burning summer sun and the bitter winter cold. The huge Saharan images--of elephant, giraffe, ostrich and other animals, human and half-human figures, and detailed geometric designs--were carved up to 11,000 years ago. …