Machu Picchu is a 15th sentury Inca citadel located in southern Peru on a 2,430 meter (8,000 feet) mountain ridge. It is the most familiar icon of the Inca empire. The Inca civilisation had no written language and no European discovered or visited the site until the 19th century. Most recent archaeologists believe that it was constructed as an estate for the Inca emperor Pachacuti (1438-1472). The estate was abandoned around 1550 at the time of the Spanish conquest.
Machu Picchu was built in the classical Inca style with polished dry-stone walls. A striking feature is that many buildings mirrored the shape of the surrounding hills and peaks - you can see that in many of the images below.