Amazon: Cities Hidden by the Forest and a History Rewritten

In 1913, former U.S. president Theodore Roosevelt and Brazilian explorer Cândido Rondon travelled through the Amazon to map an uncharted river. Accounts of the journey mention carved marks on rock and earthworks deep in the forest. The story is often dismissed as an exaggeration from the age of exploration. A century later, aircraft-mounted laser sensors scanned through the canopy and found what old maps could not show: networks of cities, raised roads, canals, and plazas.

In Ecuador’s Upano Valley, a Science study published in 2024 recorded more than 6,000 artificial earth platforms, roads up to 10 metres wide, and settlements connected in a system that lasted about a thousand years. In Bolivia’s Llanos de Mojos, a 2022 Nature study found two large centres of 147 and 315 hectares and dozens of smaller settlements built by the Casarabe culture between about AD 500 and 1400. These were not isolated huts. They were planned farming cities with ritual centres and water control.