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 were not perfect, as studies of the land show that there were landslides that happened during the construction of Machu Picchu. It can still be seen where the terraces were shifted by landslides and then stabilized by the Inca as they continued to build around the area. It is estimated that the area around the site has received more than 72 inches of rain per year since A.D. 1450, which was more than needed to support crop growth there. Because of the large amount of rainfall at Machu Picchu, it was found that irrigation was not needed for the terraces.