Machu Picchu National Geographic again and with the full support of Peruvian President Leguia. The expedition undertook a four-month clearing of the site with local labour, which was expedited with the support of the Prefect of Cuzco. Excavation started in 1912 with further excavation undertaken in 1914 and 1915. Bingham focused on Machu Picchu because of its fine Inca stonework and well-preserved nature, which had lain undisturbed since the site was abandoned. None of Bingham's several hypotheses explaining the site held up. During his studies, he carried various artifacts back to Yale. One prominent artifact was a set of 15th-century, ceremonial Incan
Machu Picchu who performed heavy physical labor (such as the Mit'a) and/or served in the Inca military. Not only people were suspected to have immigrated to Machu Picchu, there were several animal bones found that were not native to the site. Most animal bones found were from llamas and alpacas. These animals naturally live in altitudes of 14000 ft above sea level rather than the mere 8000 ft Machu Picchu rests on. Most likely, these animals were brought in from the Puna region for meat consumption and for their pelts. Guinea pigs were also found at the site in special burial caves,