Most archaeologists believe that Machu Picchu was built as an estate for the Inca emperor Pachacuti (1438–1472). The Incas built the estate around 1450, but abandoned it a century later at the time of the Spanish Conquest. It was not known to the Spanish during the colonial period and remained unknown to the outside world before being brought to international attention in 1911 by the American historian Hiram Bingham. I visited in the late afternoon during thunderstorms and the following morning.