Deep in Brazil's northeast, a massive granite arch rises from the Caatinga—Pedra Furada, a 270-meter-long rock formation carved by nature over millennia. But geology is only half the mystery. Hidden within its crevices are ancient rock paintings, reddish pigments left by prehistoric peoples who once inhabited this land. Who were they? What rituals did they perform beneath this giant stone eye? The site watches over a landscape where indigenous cemeteries and more rock art dot the surrounding hil