Hidden away in the secluded valleys of northeast Brazil and set within treacherously steep cliffs, lies some of the most significant and spectacular rock art dating to around 25,000 years ago, in the archaeological sites contained in the Serra da Capivara National Park of South America. Established in 1979 and named after the Capivara Hills, the area contains more than 300 archaeological sites, the largest and the oldest concentration of prehistoric sites in the Americas, that has created a big question mark relating to the fundamental traditional theories, underpinning the origins of human settlement in the Americas.

The scientific analyses and dating of the evidence and artefacts found in the region serve to confirm the millennial presence of human beings on the American continent, which challenges the classical theories regarding the entry route into the Americas by human populations along the Bering Strait around 10,000 BC, only moving down into Central and South America in the millennia thereafter.

Covering an area of 1291.4 square kilometers, the Serra da Capivara National Park stretches across the municipalities of São Raimundo Nonato, São João do Piauí and Canto do Buriti in the southeastern section of the Piauí state in the northeast region of Brazil. However, the southeastern region of Piauí occupies a border zone between two major geological formations, a crystalline shield from the Precambrian Period to the south and the sedimentary basin of the Silurian-Permian Sea, to the north.

In the dim past, between 440 and 360 million years ago, the region was covered by sea and the rock walls of the Serra were created underwater. However, 220 million years ago, profound geological changes transformed the landscape, when a great tectonic movement lifted the seafloor in Piauí and threw all the water into Ceará, one of the states of Brazil, located on the Atlantic coast. The resulting sediments of this trembling became part of the Serra da Capivara walls, in the layers of its great canyons. While the sediments within the sandstone formed the seabed, the extensive pebble deposit above it, gradually created an overlying ancient beach. Hidden at the base of this giant mass of rocks is a series of rock shelters and overhangs and the rock art sites have been found within these natural cathedral-like places.

However, when the last Ice Age began115, 000 years ago, Piauí became a kind of oasis, as the region never froze due to its nearness to the equator, and the highlands of the Serra became a humid tropical forest, while savanna filled the plains and fields.

But there came another climate change in the region at the end of the Ice Age 12,000 years ago, when the humidity dropped and temperatures rose sharply and over the next 3,000 years, the animals of the previous era became extinct and the vegetation changed to adapt to the new conditions. However, the abundance of archaeological sites in the Serra, full of chipped stone tools, human skeletons and cave paintings evidences that at that time, humans were also there and most of the cave paintings in Serra da Capivara were made between 6,000 and 12,000 years ago.

The Serra da Capivara National Park preserves the largest ensemble of archaeological sites and the oldest examples of rock art in the Americas, evidencing exceptional testimony to one of the oldest populations to inhabit South America. Most images of the rock art appear to be strategically placed, usually within natural depressions, either cutting into the rock surface or in eroded hollows, displaying wild animals that roamed the local ancient brushwood forest, like red deer, armadillo, jaguar, lizard, tapir and the giant rhea. The animals are either simply painted in outline or totally filled or internally decorated with geometric patterns or rows of dots. However, the large mammals are usually painted in groups and in a running stance. Apart from the display of animals, the sites of the Capivara Park, like the European cave art, are also dominated by human figures, engaged mainly in hunting or dancing. However, the walls of Capibara are a copious source of figures of people having sex, exchanging kisses on the mouth and even women giving birth, which are essential aspects of human life, but uncharacteristic of prehistoric painting. In addition to rock art, the second oldest skull in the Americas was also found in the Serra, named Zuzu, who lived 9,920 years ago.

Despite the chemical and mineral qualities of the rock on which the imageries were painted and although several panels are fragile and unstable and sections of several panels have broken away from the main rock surface due to the secretion of sodium carbonate on the rock surface over the years, the imagery on many panels in the park is in a remarkable state of preservation, due to the favourable climatic conditions. But unfortunately, the Park was abandoned for ten years, after its creation and during that period, the site was preyed upon by loggers and hunters, who became more active due to the lack of surveillance. The communities around the Park were also engaged in predatory actions, through hunting, deforestation and exploitation of limestone, resulting in the extinction of several species like deer, rheas, giant anteaters and giant armadillos. However, after ten years, the Park began to be managed by Niède Guidon, an energetic archaeologist, who dedicated her life towards researching those ancient rock sites and revealing the most important prehistoric heritage in Brazil. Today, the Serra da Capivara National Park is designated a federal heritage site, protected by law and is managed jointly by the Brazilian Institute for the Environment and Renewable Natural Resources.