Shielded by the jungle for hundreds of years, the remains of a massive 2,500-year-old network of Ecuadoran cities are being threatened by road and farm encroachment just as its long-held secrets are being revealed, researchers say.
Traces of an Amazonian "lost city" were first discovered in 1978, but the full extent of what is now believed to be the largest and oldest such urban expanse were only revealed last year with the help of laser mapping.
