Highland Peru is as extraordinary as the Inka themselves. It is the only place on earth, the Cornell anthropologist John Murra wrote, “where millions [of people] insist, against all apparent logic, on living at 10,000 or even 14,000 feet above sea level. Nowhere else have people lived for so many thousands of years in such visibly vulnerable circumstances.” And nowhere else have people living at such heights—in places where most crops won’t grow, earthquakes and landslides are frequent, and extremes of weather are the norm—repeatedly created technically advanced, long-lasting civilizations.

