Buraco das Araras is a vast quartzite sinkhole near Bezerra, about 105 metres deep and almost 300 metres across. Forest grows inside the collapsed chamber, giving the place the odd feeling of a hidden valley dropped into the ground.
Access is more awkward than Itiquira, and conditions vary, so check locally before setting out. The scale of the hole is the point; it is one of the more memorable cerrado sights near Formosa.