4. MACHU PICCHU (Perú)

Machu Picchu is a pre-Columbian 15th-century Inca site located 2,430 metres above sea level. It is situated on a mountain ridge above the Urubamba Valley in Peru, which is 80 kilometres northwest of Cusco and through which the Urubamba River flows. Most archaeologists believe that Machu Picchu was built as an estate for the Inca emperor Pachacuti (1438–1472). Often referred to as "The Lost City of the Incas", it is perhaps the most familiar icon of the Inca World.

Although known locally, it was unknown to the outside world before being brought to international attention in 1911 by the American historian Hiram Bingham.Machu Picchu was declared a Peruvian Historical Sanctuary in 1981 and a UNESCO World Heritage Site in 1983.Its three primary buildings are the Intihuatana, the Temple of the Sun, and the Room of the Three Windows.

Johan Reinhard presented evidence that the site was selected because of its position relative to sacred landscape features such as its mountains, which are purported to be in alignment with key astronomical events important to the Incas.

Different types of crops could be tested in the many different micro-climates afforded by the location and the terraces; these were not large enough to grow food on a large scale, but may have been used to determine what could grow where.