For travelers interested in archeology and anthropology, there is no better place in Brazil to have an adventure. About a 9 hour drive from hubs like Fortaleza or Salvador, this UNESCO-certified national park is an off-the-beaten-path trek into a glimpse of humankind as it survived in the arctic conditions of 30,000 years ago. In exploring the region, you'll find mountainous scrub-land dotted with rock formations and the largest rodents on the earth, the capybara.
Brazil Ecotravel, an English-language site, offers a 6 day tour of the area from Petronila (see included websites for reference). There are over 50 caves that display eons old cave drawings; Some that are especially popular with eco-trippers are Toca do Boqueirão da Pedra Furada and Baixão do Perna, where you'll find ancient instruments alongside the cave paintings.