Machu Picchu built

In the mid-1400s, the Inca built Machu Picchu on a ridge about 2,430 meters above sea level in the Andes of southern Peru, high above the Urubamba River. It was a royal estate, a country retreat for the emperor Pachacuti, who transformed the Inca kingdom into an empire. About 200 structures, including temples, residences, storehouses and fountains fed by a spring, are joined by stairways and terraces. The finest buildings use ashlar masonry, blocks cut to fit together so tightly that no mortar was needed.¹²

The estate reflected the wealth and labor the Inca state could command. Engineers terraced the steep slopes to prevent landslides and to grow crops, and built drainage under the site to cope with heavy rain, which is one reason it has survived earthquakes and centuries of neglect. Radiocarbon dating published in 2021 suggests occupation began around 1420, somewhat earlier than once thought from Spanish chronicles. Perhaps several hundred people lived there, mostly servants, and the royal household visited seasonally.³

Machu Picchu was abandoned around the time of the Spanish conquest, and the Spanish never recorded it, so it escaped destruction. Local farmers knew of it, and in 1911 the Yale lecturer Hiram Bingham was guided there, publicizing it worldwide. It became a UNESCO World Heritage Site in 1983 and is now Peru's most famous landmark, visited by more than a million people in a typical year.¹²