Rain has cut the limestone plateau of Tsingy de Bemaraha, in the remote west of Madagascar, into thousands of grey blades, some sixty metres tall. The Malagasy name means roughly the place where you cannot walk barefoot. Close up, a single blade shows what the water did: fine parallel flutes and knife edges scored into the stone over millions of years. No two are cut alike, and every one is sharp enough to draw blood. The rock is also a stack of climates. One pinnacle can hold several within a few metres: baking and bone-dry on the crest, cool and damp in the slot at its foot. That is much of the reason more than eighty percent of the plants and animals here live only here, many held to a single band of the limestone. A species can own the sunlit top of a blade and never meet the one at the bottom of it.
You go through it clipped on. Steel cables run the length of the route. It squeezes between the spikes, climbs bolted ladders and edges over footbridges strung across the gaps before opening onto the wider pinnacle field. Parts of the circuit drop off the sunlit surface into slot canyons where the blades close in overhead, the air turns cold and damp, and you shuffle sideways where the walls come together. One morning takes you through both climates. The calm half of a visit is on water. A dugout pirogue carries you down the ochre Manambolo between sheer grey walls of the same rock, past caves that hold the graves of the Vazimba, the earliest people of Madagascar. Those caves are fady, sacred, so the pirogues pass underneath and never put in to shore. Eleven kinds of lemur live in the massif, along with the fossa, the island's largest carnivore. The one everyone comes for is Decken's sifaka, white with a bare black face, which crosses the blades in long sideways bounds and lands sure-footed on edges that would open your hand.