The Inca Empire owes much to the humble llama—and to the animal’s droppings. As a 2011 study of the fallen Andean civilization revealed, llama dung served as an essential fertilizer for the Incas’ ...

Experts have shed new light on how the Inca civilization used “trophy heads” to maintain control over conquered peoples. At its height in the 16th century, the Inca Empire spanned modern-day Peru, as ...