Lost city Inca site situated on a mountain ridge above the Urubamba Valley in Peru. Often referred to as the "Lost City of the Incas", it is perhaps the most familiar icon of the Inca World. Machu Picchu was built around 1450, at the height of the Inca Empire. It was abandoned just over 100 years later, in 1572, as a belated result of the Spanish Conquest. It is possible that most of its inhabitants died from smallpox introduced by travelers before the Spanish conquistadors arrived in the area. In 1911, Melchor Arteaga led the explorer Hiram Bingham to Machu Picchu, which
Machu Picchu drawings. It was used for rites or sacrifices. The Guardhouse is a three-sided building, with one of its long sides opening onto the Terrace of the Ceremonial Rock. The three-sided style of Inca architecture is known as the "wayrona" style. In 2005 and 2009, the University of Arkansas made detailed laser scans of the entire site and of the ruins at the top of the adjacent Huayna Picchu mountain. The scan data is available online for research purposes. This semicircular temple is built on the same rock overlying Bingham's "Royal Mausoleum", and is similar to the Temple of the Sun