Hiram Bingham III Stuart McNairn whose descendants claim that they had already climbed to the ruins in 1906). Also the Cusco explorers Enrique Palma, Gabino Sanchez and Agustín Lizarraga are said to have arrived at the site in 1901. Bingham returned to Peru in 1912, 1914 and 1915 with the support of Yale and the National Geographic Society. In "The Lost City of the Incas" (1948), Bingham related how he came to believe that Machu Picchu housed a major religious shrine and served as a training center for religious leaders. Modern archaeological research has since determined that the site was not a religious
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.