Machu Picchu Picchu a "historic sanctuary". In addition to the ruins, the sanctuary includes a large portion of the adjoining region, rich with the flora and fauna of the Peruvian Yungas and Central Andean wet puna ecoregions. In 1983, UNESCO designated Machu Picchu a World Heritage site, describing it as "an absolute masterpiece of architecture and a unique testimony to the Inca civilization". Bingham was a lecturer at Yale University, although not a trained archaeologist. In 1909, returning from the Pan-American Scientific Congress in Santiago, he travelled through Peru and was invited to explore the Inca ruins at Choqquequirau in the Apurímac
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