January 6, 2010
Source: Brisbane Times
IT IS the legend that drew explorers and adventurers to their deaths: an ancient empire of citadels and treasure hidden deep in the Amazon jungle.
Spanish conquistadors ventured into the rainforest seeking their fortune. Over the centuries others followed, convinced they would find a lost civilisation to rival those of the Aztecs and Incas.
Some called it El Dorado, others the City of Z. But the jungle swallowed them and nothing was found, prompting the rest of the world to call it a myth. The Amazon was too inhospitable, said 20th-century scholars, to permit large human settlements.
Now, however, the doomed dreamers have been proved right: there was a great civilisation. New satellite imagery and overflights have revealed more than 200 huge geometric earthworks carved in the upper Amazon basin near Brazil's border with Bolivia.
Spanning 250 kilometres, the circles, squares and other geometric shapes form a network of avenues, ditches and enclosures built long before Christopher Columbus set foot in the new world. Some date to as early as 200 AD, others to 1283.
Scientists who have mapped the earthworks believe there may be another 2000 structures beneath the jungle canopy, vestiges of vanished societies.
The structures, many revealed by the clearance of forest for agriculture, point to a ''sophisticated pre-Columbian monument-building society'', says the journal Antiquity.
It adds: ''This hitherto unknown people constructed earthworks of precise geometric plan connected by straight orthogonal roads. The 'geoglyph culture' stretches over a region more than 250 kilometres across, and exploits both the floodplains and the uplands … we have so far seen no more than a 10th of it.''
The structures were created by a network of trenches about 11 metres wide and two metres deep, lined by banks up to a metre high. Some were ringed by low mounds containing ceramics, charcoal and stone tools.
It is thought they were used for fortifications, homes and ceremonies, and could have maintained a population of 60,000 - more people than in many medieval European cities. Many of the mounds were symmetrical and slanted to the north, prompting theories that they had astronomical significance.
David Grann, author of The Lost City of Z, said: ''These revelations are exploding our perceptions of what the Americas really looked liked before the arrival of Christopher Columbus.''