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 northwest edge of the rock platform points out the Solstice Window to within 2’ of the 15th century June solstice rising Sun. For comparison, the angular diameter of the Sun is 6'. The Inca constellation Qullca, storehouse, can be viewed out the Qullqa Window at sunset during the 15th century June Solstice, hence the window's name. At the same time, the Pleaides are in the opposite end of the sky. Also seen through this window on this night are the constellations Llamacnawin, Llama, Unallamacha, Machacuay, and the star Pachapacariq Chaska (Canopus). The "Intihuatana" stone is one of many ritual stones