PARIS: Archaeologists have discovered the largest and oldest network of pre-Hispanic cities ever found in the Amazon rainforest, revealing a 2, 500-year-old lost civilisation of farmers. The vast site, which covers more than 1, 000 square kilometres, was long hidden by the jungle in the Upano valley on the foothills of the Andes mountain range in eastern Ecuador. However, a French-led team of researchers have used laser-mapping technology taken from above, as well as archaeological excavations,