The Serra da Capivara national park, in the dry sertão of southern Piauí, holds the largest concentration of prehistoric rock art in the Americas. In its sandstone canyons and rock shelters there are more than a thousand archaeological sites, many of them covered in red-painted figures of deer, capybara, hunters, dancers and scenes of sex and ritual. It is a UNESCO World Heritage Site.
The park is also at the centre of a long argument about when people first reached the Americas. Excavations at the Pedra Furada shelter, led by the archaeologist Niède Guidon, produced dates tens of thousands of years older than the textbook story, and the debate over them is still unresolved. The Museu do Homem Americano in the town of São Raimundo Nonato tells that story.
The sites themselves are well laid out, with paths, walkways and lighting at the main shelters, and visits are with local guides, several of them former hunters who were trained when the park was founded. Go early or late in the day; the caatinga is very hot at noon.
It is remote — São Raimundo Nonato has a small airport, and otherwise it is a long drive from Teresina or Petrolina — which is why so few people come, and why it is so rewarding when you do.