In brief

摘要

Centuries-old Amazonian "garden cities" could serve as a model for sustainable urban development. The discovery that 600 years ago huge swathes of the western Amazon were cleared for a well-planned network of towns and villages also means that some 20,000 square kilometres of the Brazilian Amazon is not strictly "virgin" rainforest.rnIn 1993 Michael Heckenberger of the University of Florida spotted the remains of an earthen wall that ancestors of the region's Kuikuro people had built. Heckenberger and his colleagues have since traced thernextent of the pre-European settlements to produce a digital map of two complex urban clusters in the heart of the jungle.