Machu Picchu grown rapidly. In 1912, 1914 and 1915, Bingham removed thousands of artifacts from Machu Picchu—ceramic vessels, silver statues, jewelry and human bones—and took them to Yale University for further study, supposedly for 18 months. Yale instead kept the artifacts until 2012, arguing that Peru lacked the infrastructure and systems to care for them. Eliane Karp, an anthropologist and wife of former Peruvian President Alejandro Toledo, accused Yale of profiting from Peru's cultural heritage. Many of the articles were exhibited at Yale's Peabody Museum. In 2006, Yale returned some pieces but kept the rest, claiming this was supported by federal case
Machu Picchu the sun rise. Architecturally, Inti Mach'ay is the most significant structure at Machu Picchu. Its entrances, walls, steps and windows are some of the finest masonry in the Incan Empire. The cave also includes a tunnel-like window unique among Incan structures, which was constructed to only allow sunlight into the cave during several days around the December solstice. For this reason, the cave was inaccessible for much of the year. Inti Mach'ay is located on the eastern side of Machu Picchu, just north of the "Condor Stone." Many of the caves surrounding this area were prehistorically used as tombs, yet