Machu Picchu is not mentioned in any of the chronicles of the Spanish conquistadors. Apart from a couple of German adventurers in the 1860s, who apparently looted the site with the Peruvian government’s permission, only the local Quechua people knew of Machu Picchu’s existence until American historian Hiram Bingham was guided to it by locals in 1911. You can read Bingham’s own account of his ‘discovery’ in the classic book Inca Land: Explorations in the Highlands of Peru, first published in 1922 and now available as a free download from Project Gutenberg (www.gutenberg.org).

Bingham was searching for the lost city of Vilcabamba, the last stronghold of the Incas, and he thought he had found it at Machu Picchu. We now know that the remote ruins at Espíritu Pampa, much deeper in the jungle, are actually the remains of Vilcabamba. The Machu Picchu site was initially overgrown with thick vegetation, forcing Bingham’s team to be content with roughly mapping the site. Bingham returned in 1912 and 1915 to carry out the difficult task of clearing the thick forest, when he also discovered some of the ruins on the so-called Inca Trail. Peruvian archaeologist Luis E Valcárcel undertook further studies in 1934, as did a Peruvian-American expedition under Paul Fejos in 1940 and 1941.

Despite scores of more recent studies, knowledge of Machu Picchu remains sketchy. Even today archaeologists are forced to rely heavily on speculation and educated guesswork as to its function. Some believe the citadel was founded in the waning years of the last Incas as an attempt to preserve Inca culture or rekindle their predominance, while others think that it may have already become an uninhabited, forgotten city at the time of the conquest. A more recent theory suggests that the site was a royal retreat or the country palace of Pachacutec, abandoned at the time of the Spanish invasion. The site’s director believes that it was a city, a political, religious and administrative center. Its location, and the fact that at least eight access routes have been discovered, suggests that it was a trade nexus between Amazonia and the highlands.

It seems clear from the exceptionally high quality of the stonework and the abundance of ornamental work that Machu Picchu was once vitally important as a ceremonial center. Indeed, to some extent, it still is: Alejandro Toledo, the country’s first indigenous Andean president, impressively staged his inauguration here in 2001.