Four large huts spotted in the Amazon from an airplane indicate an amazing discovery: an uncontacted tribe in Brazil. The huts are thatched and surrounded by crops. Researchers will not make contact with the tribe, since tribe members might not have immunity to outside diseases. They are in the Vale do Javari region along the Peru border—an area thought to have the highest number of uncontacted tribes in the world. In recent years, Brazil has discovered a dozen previously uncontacted troops in the Vale do Javari, which is thought to be home to some 2,000 people.