I visited Serra da Capivara NP some months ago. Truly an amazing experience. It takes time and planning to get there, as the closest airport is 400 km away, but newly paved roads make it accessible.

It usually takes three days and lots of hiking with an accredited guide to spot the most famous rock paintings the park is famous for. Most of them are 6.000 to 12.000 years old, but some are said to be much older - some researchers belive that's the proof that the first Americans also came from Africa, crossing the Atlantic Ocean during Ice Age, and not only from Asia through Alaska.

The painting are plentiful and depict various themes such as hunting and adoration, but also regarding sex intercourse, animal habits, honey collecting, etc.. Very interesting indeed.

There is very little left in Brazil about human activity before the Portuguese colonizers. Serra da Capivara is a remarkable exception.