Chapada dos Veadeiros is a plateau of bare quartz and tiered waterfalls in Goiás, in central Brazil, and most of what is on it has gone from everywhere else. It guards the purest surviving stretch of the cerrado, the ancient savanna of the country's interior, cleared across most of its range for soy and cattle. Here it stands whole: twisted trees, tall grass, maned wolves, giant anteaters and rheas out on the plains. The rock underneath is quartzite laid down about 1.8 billion years ago, among the oldest exposed surfaces on Earth, and it decides what the water is like. The rivers here run over crystal rather than mud, so they come off the plateau almost clear.
The Saltos do Rio Preto are the centrepiece, twin drops of 120 and 80 metres into a canyon at the end of a long walk from the village of São Jorge. You wade into cold pools over pale stone at the bottom. Late in the morning the sun comes round onto the falling water, and the mist splits into a rainbow standing in the gorge. Upstream the river steps from one rock terrace to the next, each shelf holding its own shallow pool. Where it runs deep and green between the walls, people climb the ledges and jump. The trail takes you on into the canyons, between quartzite walls the river has been cutting for hundreds of millions of years. Just outside the park the São Miguel has polished grey rock into a field of smooth hollows and basins that you cross barefoot, the Vale da Lua. The name of the plateau means the plateau of the deer hunters, after the men who tracked wild deer up here with dogs. The valleys around it kept something else. The Kalunga are descendants of Africans who escaped the gold mines of Goiás two centuries ago and hid in these highlands. Some nine thousand of them now hold the largest quilombo territory in Brazil, and several of the best waterfalls stand on their land, where they take you in themselves.