It is thought the city was built by the Inca emperor Pachacuti starting in about 1440 and was inhabited until the Spanish Conquest in 1532. Archeological evidence (together with recent work on early colonial documents) shows that it was not a conventional city; rather it was a sort of country retreat town for the Inca Emperor and nobility. The site has a large palace and temples around a couryard, with other dwellings for the support staff. It is estimated that a maximum of only about 750 people resided in Machu Picchu at any one time, and probably only a small fraction of that number during the rainy season and when no nobles were visiting.
The city was re-discovered on July 11, 1911, by a Yale historian, Hiram Bingham, who was exploring old Inca roads in the area. Bingham made several more trips and conducted excavations on the site through 1915. He wrote a number of books and articles about Machu Picchu; his popular account Lost City of the Incas became a best-seller.
The site is a UNESCO World Heritage Site and a popular tourist attraction. In 2003, some 400,000 people visited Machu Picchu, and UNESCO has expressed concern about the damage this volume of tourism is causing to the site. Peruvian authorities insist that there is no problem, and that the remoteness of the site will impose natural limits on tourism . Periodically, proposals are made to install a cable car to the site, but such proposals have so far always been rejected. .
One of the Chilean poet Pablo Neruda's best-known works is "The Heights of Macchu Picchu", inspired by the city.