Simon Romero – NY Times, 01/14/2012
Edmar Araújo still remembers the awe.
As he cleared trees on his family’s land decades ago near Rio Branco, an outpost in the far western reaches of the Brazilian Amazon, a series of deep earthen avenues carved into the soil came into focus.
“These lines were too perfect not to have been made by man,” said Mr. Araújo, a 62-year-old cattleman. “The only explanation I had was that they must have been trenches for the war against the Bolivians.”