Machu Picchu was constructed around 1460, at the height of the Inca Empire. It was abandoned less than 100 years later. It is likely that most of its inhabitants were wiped out by smallpox before the Spanish conquistadores arrived. Hiram Bingham, the credited discoverer of the site, along with several others, originally hypothesized that the citadel was the traditional birthplace of the Inca people or the spiritual center of the “Virgins of the Suns” (Bingham, Inca Land:Explorations in the Highlands of Peru, p.334).

Another theory maintains that Machu Picchu was Inca “llacta”: a settlement built to control the economy of the conquered regions. It may also have been built as a prison for a select few who had committed heinous crimes against Inca society. Research conducted by scholars, such as John Rowe and Richard Burger, has convinced most archaeologists that rather than a defensive retreat, Machu Picchu was an estate of the Inca emperor, Pachacuti. In addition, Johan Reinhard presented evidence that the site was selected based on its position relative to sacred landscape features. One such example is its mountains, which are purported to be in alignment with key astronomical events.

Although the citadel is located only about 80 kilometers (50 miles) from Cusco, the Inca capital, it was never found and consequently not plundered and destroyed by the Spanish, as was the case with many other Inca sites. Over the centuries, the surrounding jungle grew over the site, and few knew of its existence. On July 24, 1911, Machu Picchu was brought to the attention of scholars by Hiram Bingham, an American historian then employed as a lecturer at Yale University. He was led there by locals who frequented the site. Bingham undertook archaeological studies and completed a survey of the area. Bingham coined the name “The Lost City of the Incas”, which was the title of his first book. He never gave any credit to those who led him to Machu Picchu, mentioning only “local rumor” as his guide.Bingham had been searching for the city of Vitcos, the last Inca refuge and spot of resistance during the Spanish conquest of Peru. In 1911, after years of previous trips and explorations around the zone, he was led to the citadel by Quechuans. These people were living in Machu Picchu, in the original Inca infrastructure. Even though most of the original inhabitants had died within a century of the city’s construction, a small number of families survived so by the time the site was ‘discovered’ in 1911, there were still mummies (mostly women) in Machu Picchu and some families still living on the site. Bingham made several more trips and conducted excavations on the site through 1915. He wrote a number of books and articles about the discovery of Machu Picchu in his lifetime.

Simone Waisbard, a long-time researcher of Cusco, claims that Enrique Palma, Gabino Sánchez, and Agustín Lizárraga left their names engraved on one of the rocks at Machu Picchu on July 14, 1901. This would mean that they ‘discovered’ it long before Bingham did in 1911. Likewise, in 1904, an engineer named Franklin supposedly spotted the ruins from a distant mountain. He told Thomas Paine, an English Plymouth Brethren Christian missionary living in the region, about the site, Paine’s family members claim. In 1906, Paine and another fellow missionary named Stuart E McNairn (1867–1956) supposedly climbed up to the ruins.

In 1913, the site received significant publicity after the National Geographic Society devoted their entire April issue to Machu Picchu. In 1981 an area of 325.92 square kilometers surrounding Machu Picchu was declared a “Historical Sanctuary” of Peru. In addition to the ruins, this area includes a large portion of the regional landscape, rich with flora and fauna.Machu Picchu was designated as a World Heritage Site in 1983 when it was described as “an absolute masterpiece of architecture and a unique testimony to the Inca civilization”.[3] On July 7, 2007, Machu Picchu was voted as one of New Open World Corporation’s New Seven Wonders of the World. As a result of environmental degradation resulting from the impacts of tourism, uncontrolled development in the nearby town of Aguas Calientes (including a poorly-sited tram to ease visitor access), and the construction of a bridge across the Vilcanota River in defiance of a court order and government protests (which would most likely bring even more tourists to the site), the World Monuments Fund placed Machu Picchu on its 2008 Watch List of the 100 Most Endangered Sites in the world.