Spirits in the sky at a royal retreat

On July 24, 1911, a young Harvard University history professor named Hiram Bingham gazed for the first time on what was to become one of the 20th century's greatest archaeological discoveries - the Inca mountain-top city of Machu Picchu. Tipped off in Cuzco, and eventually guided to the site by local farmers, Bingham discovered what the Spanish conquistadors had missed - an almost perfectly preserved Inca settlement, only a few days away from the imperial Inca capital.

Enveloped in mist, invisible from the river valley below, this all but inaccessible jewel of Inca architecture was a mystery and an enigma. Who had built it, when and why? Since the city's rediscovery, and despite innumerable reissues of Bingham's several books on the site, Machu Picchu has not received the attention it merits. In Machu Picchu: Unveiling the Mystery of the Incas , the Andean specialists Richard Burger and Lucy Salazar have produced a scholarly yet accessible and profusely illustrated book that redresses the balance. Each chapter deals with an aspect of the city's history and archaeology. Many and varied have been the interpretations of this dramatically sited city. Fortress, priestly centre, mythical birthplace of the Incas and astronomical observatory are all tags that have been attached to it.

In search of the answer to Machu Picchu's purpose, Salazar builds on the original insight of the Andean scholar John Rowe. Rowe's work in Cuzco's archives identified Machu Picchu as part of a royal estate belonging to the Inca emperor Pachacuti - the driving force behind imperial Inca expansion during the mid-15th century AD. Salazar and Burger's analysis of the pottery has added archaeological weight by discovering a lack of earlier pre-imperial ceramics.

It seems that, as with other royal estates at Pisac and Ollantaytambo, Machu Picchu was originally a commemorative site of Pachacuti's military victories that was transformed into a royal retreat and country palace as the frontier moved on. Used for high-status relaxation and entertainment, it existed only because of the elaborate state-funded support system that ferried in food, drink, clothing and luxuries. Once the Spanish had destroyed Inca economic and administrative organisation, Machu Picchu was unable to survive and was quickly abandoned.

In her contribution, Susan Niles broadens the discussion to explore what Inca royal estates were and how they functioned. We see how they had varied purposes, linked to the Inca political economy, and played an integral role in the dynastic politics of different royal clans. Royal estates were also part of religion and spirituality, providing the agricultural and labour basis for supporting descendants and honouring ancestors.

Filling out the picture at ground level is a welcome synthesis of recent archaeological work at the site by Alfredo Zegarra, a Peruvian archaeologist. A new Inca road has been discovered that leads from the city storehouses down to the valley bottom. Paved with stone slabs and incorporating stone-built staircases, this remarkable piece of engineering is 1.6km in length, yet descends some 525m. Equally insightful were the excavations on the city's eastern slopes. Here, burial goods included cooking pottery and metal items such as brooches, mirrors and pins.

In a penultimate flourish, we are taken by Jorge Ochoa on a voyage of discovery into the New Age of Machu Picchu. Here we see how Pachacuti's royal estate is presented to and understood by the waves of modern tourists who flock to encounter the numinous spirits among its precisely carved and fitted polygonal blocks. For Machu Picchu is an icon not just of the Incas, or of Peru, but also of the multiplicity of ways in which people today view the past. Eco-tourists see a city blended with nature, and mystical tourism connects with the spirituality of mountains and freshwater springs as sacred places. Even UFOs are sought, by people stimulated by actress Shirley Maclaine's book and film about her close encounters in Inca surroundings.

And, as if to balance the modern with the ancient, the editors themselves produce a final catalogue of "the most memorable objects" recovered in 1912 and by subsequent expeditions from Yale University. Aside from Bingham's Kodak Folding Pocket Camera, we see the distinctive Inca aryballus - ceramic jar - covered with neat geometrical designs, miniature ceramic corn cobs used to petition the gods for abundant harvests, silver pins called tupu for fastening Inca shawls, bronze mirrors and small gold and silver figurines. This is a new vision of Machu Picchu, a royal city dedicated to sumptuous living and the rituals of state religion. After almost a century, we are finally gaining a deeper insight into this magnificent site and observing also how it changes to meet the times. Every age, it seems, gets the Machu Picchu it deserves.

Nicholas J. Saunders is in the department of anthropology, University College London.