When you think of the treasures of the ancient cultures of South America, you usually think of shiny gold and fine silver work. But for the Chincha people, who built one of the wealthiest empires on Peru’s Pacific coast between 1000 and 1400 CE, the real gold lay in a far less glamorous substance: seabird droppings. The seemingly banal excrement was the fuel for an agricultural revolution in one of the driest regions on earth 800 years ago.
