Peru, Andes,Dung loaming: how llamas aided the Inca empire

Research shows that Incas built citadels such as Machu Picchu after the earlier achievement of agriculture at high altitudes through the use of llama dung. Manure from llama herds provided fertiliser which enabled corn to be cultivated at very high altitudes, allowing the Inca civilisation to flourish in the Andes and conquer much of South America, according to research. Read Article