The Amazon rain forest, long thought untamed by human hands, was once the site of an enormous and sophisticated urban community, says Science. In 1925, British explorer Col. Percy Fawcett set off in search of a rumored lost Amazon city, but disappeared into the jungle, never to be heard from again. Fifteen years ago, anthropologist Michael Heckenberger was studying the same part of the Amazon when a village chief showed him the remains of an ancient earthen wall far out in the jungle. The tribe believed the wall had been put there by God, but Heckenberger quickly realized it was a remnant of an ancient human settlement. Since then, he’s uncovered a host of archaeological evidence indicating that the Amazon once held an extensive network of structured settlements and towns over an area as large as the state of New Jersey.
These semi-urban settlements were built about 1,500 years ago and stood for a millennium. Though not as elaborate as Mayan settlements in Central America, these 15 cities and villages were home to an estimated 50,000 people who interacted via a network of well-worn roads. Each city was surrounded by a protective wall and satellite settlements. Nearby, the inhabitants farmed and raised fish for food. When Europeans arrived in the 16th century, the diseases they brought wiped out this indigenous civilization, and the area became overgrown with jungle once again. “What we think of as the primitive Amazon forest is not so primitive after all,” Heckenberger says.